vmm32.vxd problem when upgrading RAM

[ScrewUpgrading]

Whenever I try to install the maximum 512 MB Ram that my computer can handle I always get the error, when rebooting, "missing or corrupted C:\WINDOWS\SYSTEM\VMM32.VXD."

I've gotten the BIOS to identify 512 MB, but then while booting to Windows it stops and hangs with that message on the screen.

I did try adjusting the maximum memory size using "msconfig > advanced > limit memory size to 512". But still it didn't change anything.

Is there something about "168 pin low density sdram" that I'm missing, because that's what it requires, and that's what I've been trying. I've probably tried about five or six different sticks of ram in different combinations.

The weird thing is that I have to have my hewlitt packard RAM in the first slot of the two, otherwise nothing else will work.

Should I just keep trying pairs of RAM on this thing until i get lucky and a pair actually works?

Here's what I have:

Slot 1 = 128 MB stock memory that came with computer from Hewlit Packard. <-- I'm thinking this is the only "brand" that will work on this piece of junk

Slot 2 = some random 256 MB stick

total = 384 Mb ram

Well, I've pretty much given up on maxing out my RAM, I was just wondering if anyone could tell if I was doing something blatantly wrong. Otherwise I'll just chalk it up to HP being morons.

Edited September 19, 2011 by ScrewUpgrading

[rilef]

Memory does not need to be a specific brand, but must match the requirements of your motherboad and settings. For example, memory may have to be of a specific speed or higher; memory may have to installed in a specific order; or memory may be best installed, or required to be installed, in matched pairs. Thus, to start, you may want to try downloading an owner's manual for your computer model from HP. Another source, of your computer's memory requirements, may be memory vendors on the internet.

[technoid]

What is the model # of this HP machine? What is the CPU? I assume it is Windows 98SE (since you're posting in this subforum). Yes, it is possible it will need a specific make of ram. I have an eMachines that is also as stubborn. Sometimes it can be how many chips there are on the memory stick. Are these PC100 or PC133... or DDR? Don't know until you give us more info and specs. Since you are getting this error when you start Windows, then this means that at least you can get the machine to boot properly first. What about Windows Safe mode, can you get into that?

You can also go to the HP store online and find what memory specs are required for this machine. Of course their prices will be through the roof, but at least you can see what memory description is at least required. Yes, get the manual as Rilef mentioned.

[ScrewUpgrading]

http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph06462&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=61776

From the HP official website:

HP Pavilion 7845

RAM (standard) 128 MB RAM PC100

Maximum 512 MB (2x256 MB DIMM)

Speed 100 MHz synchronous

Sockets 2 – 168 pins DIMMs

Size 32, 64, 128 and 256 MB DIMMs

Free DIMM Sockets 1

Pairs Required No

Type Supported SDRAM, Intel PC SDRAM unbuffered DIMM specification, revision 1.0 compliant

866 MHz

Windows ME

*More info*

HP Website couldn't find a manual for my specific model. Must be too old.

One important thing I noticed is that the RAM that came with it, a 128 MB stick, only has chips on one side, the other side is flat.

If I put a 256mb pc100 or pc133 stick in the first slot, the computer won't recognize any Ram at all. But if I have the HP 128 Mb stick (the one with a flat side) in the first slot, then the 256mb sticks will work in the second. It's weird.

Edited September 20, 2011 by ScrewUpgrading

[rilef]

One important thing I noticed is that the RAM that came with it, a 128 MB stick, only has chips on one side, the other side is flat.

If I put a 256mb pc100 or pc133 stick in the first slot, the computer won't recognize any Ram at all. But if I have the HP 128 Mb stick (the one with a flat side) in the first slot, then the 256mb sticks will work in the second. It's weird.

The HP Pavilion 7845 has 2 bank(s) with 1 slot in each bank. Thus, the HP memory module, or any other module, should work standalone in either slot. If not, there may be something wrong with the second slot. Make sure that the slot is clean and the module is properly seated. Also, make sure the memory modules themselves are clean.

The newer PC133 memory modules are supposed to be backward compatible to PC100, and should work standalone in either slot, or together with another PC100 or PC133 module. Are you sure that your 256MB module(s) aren't bad?

The number of chips on the module should not matter. However, the modules of the same memory size but with fewer chips- these modules tend to be manufactured later, with better quality (especially if made by major manufacturers, rather than generic). Fewer chips also make the module easier to install.

[TmEE]

Flip the sticks around and see if it makes a difference, if it does then you got a faulty stick and should not use it. If the result is still same you may have a bad slot, in which case try booting with one stick in the other slot and if problem is still there with both sticks you nailed the problem.

[ScrewUpgrading]

Thanks you guys.

I'm going to try and find some better quality ram sticks, the ones I have were old and they cost a dollar :-).

[technoid]

I found manuals at the HP site, but they did not really give me any more info than what the official listed specs already stated.

The 7845 page is at: http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&dlc=en&product=61776&lc=en&jumpid=reg_R1002_USEN

You have to search by using the actual part # of this PC, which is "P3928A" as listed in the product spec page.

Can you also check what BIOS is presently on your machine? BIOS and other firmware are available at this page, but be cautioned that this can be a dangerous procedure if you don't know what you're doing. Look in the Software/Downloads section for Windows Me stuff to find the BIOSes. And drivers you think you may need. Anyway, BIOS revisions could also help your PC become better, but at this point, I'd worry with your ram situation first. I was just giving you heads up.

The 7845 utilizes the i810e chipset. This chipset can handle PC133 memory, since we are talking about the Pentium III. I realize the 7845 came with a 128MB PC100 stick. This is really due in part to economics. HP and other manufacturers will give you minimum specs to keep overall system costs down. You did not really state what speed was your 256MB stick you were using. And also, while PC133 in theory and design can be downward compatible with PC100 memory, especially when you mix them together, in practice this may not be always true. It really does depend what your model PC (any model PC) was designed to operate with. And also as aforementioned, it can be due to glitches, whether by a broken discrete part, or dust, or a connector problem, etc etc. A memory stick, even if you thought should work, can also give you POST errors.

A list of Intel chipsets: http://en.wikipedia.org/wiki/List_of_Intel_chipsets

In this case you really ought to buy the maximum amount of memory to get as much out of that PC before its usefulness becomes less viable over time. An 866Mhz system is still very functional these days. You will get a nice little speed boost from PC100 to PC133, and better system handling at 512MB (max). That's if all your memory is at PC133. You will have to judge the speed boost by yourself (e.g. eyeballing) and/or with a benchmark program.

Since your system is able to run with the PC100 128MB stick, then that is the overall memory speed your PC is running at, regardless if that 256MB is at PC133. You can find 512MB PC133 anywhere (at 2 x 256MB sticks). I've had lots of success over at eBay. It's up to you to try it. Here is one list (sorted as Buy It Now only, Lowest prices first, and in New condition):

http://www.ebay.com/sch/i.html?LH_BIN=1&rt=nc&LH_ItemCondition=11&_nkw=pc133%20512%20256&_clu=2&_fcid=1&_fln=1&_localstpos=97071&_sc=1&_sop=15&_ssov=1&_stpos=97071&_trksid=p3286.c0.m1539&gbr=1

As you can see there, you could potentially buy two 256MB sticks at total of $8.00, new. If they don't work on your 7845, you can always return them (always check seller return policies first before buying).

I have similar PC, but a little more modern, i.e. the HP Vectra VL400 desktop tower (815 chipset, Pentium III 1.0 GHz). Got this whole system (PC, monitor, printer, software, etc) for free back in 2001 when I used to work at Intel. Actually I got two of them (a co-worker gave hers away to me several years later). I formatted one for Win 98SE. And the other is on Win 2k... this is my HTPC, home theater PC, running a DLP projector via DVI. And with surround sound, of course. .

Oh and back to your original issue, I don't really know what's going on. I've had VMM32 issues before, just don't remember how they got fixed. This might help: http://support.microsoft.com/kb/194679 , in addition to obtaining proper ram sticks. And/or keep Googling, heh. Good luck.

Edited September 20, 2011 by technoid

[bphlpt]

For a motherboard that old, and I have some of similar vintage myself and older, double check to see if there is a jumper or switch to set for using PC100 vs PC133. You'll need to check the manual to be sure, but usually if there is one it is around the memory sockets somewhere, and it will be small and probably not well marked. If you have such on that motherboard, and it's setting doesn't match your memory, especially if your memory is a mix of the two, you could get unpredictable results. Good luck and let us know how it turns out.

Cheers and Regards

[ScrewUpgrading]

Thanks you guys, lots of good info. I'm going to look for those possible jumpers that were mentioned.

technoid, I followed your link on ebay and found this listing:

http://www.ebay.com/itm/SDRAM-Lot-2-x-256MB-512MB-PC133-SDRAM-Desktop-Mem-RA-/110703492411?pt=LH_DefaultDomain_0&hash=item19c6713d3b

I was thinking of buying it.

The motherboard is the "cognac" series.

Phoenix BIOS:

Core version 4.06

BIOS Revision 2.07 03/09/01

=============================================

*edit*

I downloaded the newer BIOS revision (2.11) and studied the release notes. Nothing was mentioned about fixing RAM problems. Instead, it updates the toggle switch for Fan #3, includes some patches for the modem under WinXP, and some other non-essential stuff. I don't really see any point in upgrading the BIOS, in that case. So, I'll leave well-enough alone.

I'm nearly %100 positive that this machine only takes Hewlett Packard proprietary RAM. Which at this late date would be near impossible to find, unless I found another computer of the exact same model and year with 512 already installed, and I could just steal them. Trust me, I've tried plenty of memory sticks on this machine. Everything worked fine, as long I had the original HP memory (128 MB PC100) in the first bank. I think most of the chips I bought worked fine, because I was able to get 384 MB with all of them. (128 Mb original proprietary + any 256 Mb stick I threw at it = working 384 Mb RAM).

In that case, I don't think it's a problem with the motherboard, or the Bios, or any hardware defect. I think it's solely a matter of this computer only being able to be upgraded with crappy proprietary RAM from HP.

I was mainly interested in finding out about the "missing or corrupted C:\WINDOWS\SYSTEM\VMM32.VXD" issue, because that's such an unusual error message. I thought maybe it could be fixed by tweaking something in Windows before installing new RAM. But, I don't know. I tried Googling it and found that someone else had a similar problem, and he also came to the conclusion that this computer is just REALLY PICKY about what RAM goes into the first bank. I'm not a tech person or anything like that, but I think he has it nailed.

I've already wasted like 50 dollars on RAM sticks for this thing, and I don't think any more will make a difference, as tempting as it is to try and hold out hope.

I looked for possible jumpers near the memory banks, didn't see anything. And I looked into the BIOS revision that technoid mentioned, but after reading through the release notes, nothing was mentioned about RAM upgrades or anything like that.

So, I'd rather just leave well-enough alone concerning upgrading the RAM and BIOS. I guess if it ain't broke, then don't fix it.

Edited September 20, 2011 by ScrewUpgrading

[ScrewUpgrading]

*Problem Solved*

It is the motherboard.

After searching Google I found this page at the HP help forum:

http://h30499.www3.hp.com/t5/Home-PCs-Pavilion-Presario/vmm32-dll-error-Memory-errors/td-p/46512

Pavilion 7845

Added Crucial 2x256MB PC133 SDRAM

When the computer boots up there is an error with vmm32.dll. Take one of the Modules out and the computer boot up fine. Put the original 64MB in By itself or with either of the 256 DIMMS it boots up fine. In any combination, boot up fine. Put the 2 256 DIMMS in and it gives an error in vmm32.dll. If anybody has any insight on why this would do this it is appreciated.

We are the music makers, and we are the dreamers of a dream

For everyone else having this problem. I just got off the phone with HP support AGAIN. After many days of trying to sort this out, they say the problem is on the motherboard. So my unit will be shipping back for repairs. So if you are having the same problem and still under warranty call them and make them fix this for you.

I wonder if my computer is still under warranty? LOL!

So, technically, my computer IS maxed out as far as RAM.

Woohoo! 384 Mb!

Edited September 20, 2011 by ScrewUpgrading

[technoid]

Oh that is sad. An "oldish" PC that has great potential when max'd out. Of course it's not old by my standards, I still have PC/XT's and Commodore 64's in working condition. Well, you can always contact HP and see what they would offer for repair. Or go back into the HP forums and try to pry out more tech info as to what's going on on the motherboard. Your last resort would be to buy, yet again, that $8-$9 set of DIMMs, just to eliminate further doubts. It's a good machine, but at 384MB, it won't help run XP as efficiently as it would on ME/9x, if you decide to update the O/S. I've got that eMachines on XP, and at 384MB it's frakking slow. Actually, in addition to that, it's also a 1.0 GHz Celeron and 4200rpm drive, which multiplies that slowness even more. I am eventually upgrading those parts to max it out, i.e. replace Celery with Pentium III 1.0 GHz, replace 4200rpm to 7200rpm drive, and max out ram to 512MB (at PC100 to PC133, since Celeron uses only PC100).

You never did say what speed rating that 256MB stick was at. If it's PC133, then I would probably use that instead if it can boot. If you can only max out at 384MB, have you already tried a 128MB stick in one slot and a 256MB stick in the other, but both at PC133? Sometimes I tend to go for that speed boost first, with capacity as secondary, you just have to judge the balance you require. That Win2k HTPC of mine is still at 384MB (512MB max, PC133) and it plays movies fine.

But, make sure to be sure, that your mobo really needs that mobo fix. Don't settle yet on what you've discovered. You could potentially have a mobo that already has that fix and this issue can still be something else. Find any labeling on the mobo about any fixes or revision numbers. You can also reply to in that HP thread (as opposed to making a new one there), if it's not closed yet. Good luck again and hopefully you'll also burn to the latest BIOS (be careful) just to eek out more upgrades. Or you can just sit back, relax and say "F*** IT".

[ScrewUpgrading]

Yeah, that thread was from 2001. I'm pretty sure it's been closed down by now.

384 is fine for Windows me. And in my mind now, it is maxed out.

Speaking of oldish computers, I have fond memories of my first computer: IBM PS/2, 386sx, 4mb Ram, 80 Meg Hard drive, DOS 5.5 & Windows 3.1. Don't suppose you have any of those beauties laying around?

The only upgrade I ever made was adding a Cirrus Logic graphic card. Boy, that did wonders. I went from VGA (320x200x256 colors) to SVGA (640x480x32k colors).

I wish I still had that thing. I actually used it until the year 2000 because I remember in my senior year in high school I typed a paper on it using a freeware DOS text editor

You can get an idea of how long I stick with computers. I'm only on my third computer since, oh, 1991 I think.

[technoid]

Yes I still have many old "beauties" around, not exactly what you have, but plenty of them. PC/XT's (8088/8086), 80286's, 486's, earlier Pentiums, AMD K6's, NexGen, three C-64 systems, etc. No PS/2's though. I do have a 386 board, but it is experimental and unbugged (many wirewraps on it) and has never fully worked (has proprietary keyboard connection and BIOS), I never bothered to look into it further. Half of these PC mobo's are in ESD bags, buried in cardboard boxes, I just hate to throw them out. Plenty of old PC cases too (half are desktop, half are towers). Yes, many harddrives, some going back to half-height MFM 40MB. Many sticks of RAM, going back to 30pin SIMMs and also individual SRAM DIP IC's you have to plug into IC sockets on mobo. I actually do have a couple of CL videocards as well, which can handle 1024x768 43Hz interlaced. I just recently had one of my old monitors (which could only do 1024x768 interlaced) die a horrible death a few days ago. Something smoked inside, I haven't opened it up yet, it did smell up the room badly of burnt silicon. I've been using it since like 1992. I've since replaced it with another monitor of the same era, lmao. Many old printers too (dot matrix, lasers, from the past 3 decades). I like trying to restore and maximize these puppies to their fullest, and maybe beyond. MSFN.org helps us very well in obtaining those goals as much as possible, and for as long as possible, until these operating systems and hardware become finally useless, less so than a handheld calculator, heh. For example, I've used 98SE2Me before, which uses the best of both worlds of 98SE and Me. Soporific's Autopatcher gets my 98SE up to date, as well as KernelEX, RP, et al. You mentioned typing up papers. I used my Commodore64 to type up papers in college 2 decades ago. The operating system GEOS64 and a dotmatrix printer. And before that I was typing on a typewriter for highschool papers. Still have my 1901 Royal typewriter, heh. Heavy as heck.

And yeah I still have my original Windows 3.x installation floppies. If you wish to try Win 3.x again, there is a graphical shell that can make it function like the Win 95 (thru Win 7) desktop, which you can get at http://calmira.de .

[ScrewUpgrading]

Calmira looks pretty cool. I don't know if I'd use Windows 3.1 again though (not enough software for it), I might as well just use DOS if that was the case

I used to use this "Access" menu program on my DOS machine:

http://surf.to/AccessDosMenu

I don't know if you have one, but where I live there's a "Re-Electronics" store where people can take their old, unwanted computers. They have volunteers who refurbish them, install a newer OS (usually Ubuntu or Windows XP) and they sell them for like 100$. Better than buying off ebay.

Last time I was there they had dozens of Pentium IV machines with 1 Gig Ram and Ubuntu for 75$-100$. They also sell CRT monitors, LCD Monitors (I got mine for $40 bucks), keyboards, mice, Ram, Hard drives, VCR's, and other stuff.

Alot of the stuff they have would be perfect for building a Win9x dream machine. They have all sorts of old junk there. I'm going there tomorrow. See if I can find some cheap junk.

Maybe they have a location near you.

http://relectronics.org/index.php/links

Edited September 21, 2011 by ScrewUpgrading