Both KB4484243 and KB4484236 installed OK via Automatic Updates. Didn't have to search for them. No adverse effects so far.

8 hours ago, Dave-H said:

KB4484243 is an update for Excel, the program executable and the converter, so I guess it wouldn't install if Excel wasn't enabled?

Presumably not, but I do have Excel 2010 installed

I'll try downloading it and installing it manually, I guess

Found it!

I actually have two Excel versions on my VM: Excel 2000 and Excel 2010. Because I want .xls files to open in 2000 and .xlsx files to open in 2010, I altered the shell registry entries for both. Otherwise double-clicking a spreadsheet file tries to use DDE, which tries to open the sheet in whichever version is open. Obviously, if 2000 is open and I double-click an .xlsx file, that fails miserably.

But I've been having a problem: something keeps going in and resetting all my shell registry entries, forcing me to fix them over and over. So I went into regedit and revoked permission to change these entries.

And guess what? It's these monthly "security" updates that have been resetting my shell registry entries! And now that it's not allowed to do that any more, the update fails to install.

Ah, all is revealed!

So, taking off those "deny" permissions fixed it.

I guess from now until Office 2010 EoS, I'll need to delete the Excel.Sheet.12\shell key and re-import my custom changes after each month's updates.

The only thing I can't figure is why a "security update" even bothers resetting those registry entries. Maybe it just runs "Repair Office Installation" under the covers after it replaces the files included in the update.

Two updates today, KB4484267 for Excel, and KB4484163 for Outlook.
Both installed with no problem and everything is fine.
Still a very long scan on Microsoft Update, but it got there in the end!

 

Just one update for Word this month, KB4484240.
Installed via Microsoft Update with no problems.
The clock is ticking down to end of support in October, but let's hope future updates stay XP compatible until then!

Edited March 11, 20206 yr by Dave-H
Typo

another new mso.dll office 2010 security update that XP users should avoid installing - KB4484126 (which replaces KB4464566)

Edited April 14, 20206 yr by erpdude8

Thanks!
Yes, when I saw there was 11 updates for Office 2010 on Windows 10 this month I had a nasty feeling that there would be a bad one in there for XP!
First time since the end of last summer though, so not too bad.
I just replaced the "bad" MSO.DLL with the last working one (14.0.7214.5000) and all is well again.

OK, I'm planning to install/upgrade my old copy of Office 2010 on this old XP install I've resurrected, but I want to know which updates have the bad MSO.dll file so I can avoid them.

Without having to read the past 15 pages, is there a definitive list of every to-be-avoided update released thus far?

c

I wouldn't worry about being given loads of faulty updates by Microsoft Update, you should only be offered the one with the latest MSO.DLL in it (KB4484126).
That is faulty, the one you will have to find manually on the Update Catalogue and install manually is KB4092483, which contains the last working MSO.DLL for XP, version 14.0.7214.5000.
In fact, if you can unpack it, you only need to substitute the MSO.DLL file from it in Program Files\Common Files\Microsoft Shared\Office14.
If you do that, any other files that were in KB4484126 will be preserved.

Perfect!  That's exactly what I wanted to hear!

Armed with this information, I shall now go install and update Office worry-free 

c

On 4/15/2020 at 12:50 AM, Dave-H said:

...the last working MSO.DLL for XP, version 14.0.7214.5000.
In fact, if you can unpack it, you only need to substitute the MSO.DLL file from it in Program Files\Common Files\Microsoft Shared\Office14.

@Dave-H. That worked a treat. Saved messing about removing update/s. Thankyou for sharing that work-round.

No problem, glad it worked OK for you!

After installing the broken update, Office 2003(yes I have two office versions installed, 2003 & 2010) refused to open any .docx files, but after replacing with the older MSO.DLL, it was back on working again