Very much like MSE 4.4.304.0 (manually) installed on Vista SP2, the native anti-spyware implementation, aka Windows Defender, ceased receiving definitions update via Windows Update itself sometime after the July 9th deadline; as posted here, the last def update (v1.297.531.0) I got through WU was on July 6th...
Similarly, invoking a manual definitions update via the WD GUI:
always results in
So, currently, the ONLY way of updating WD def files on Vista SP2 is by manually downloading file mpas-fe.exe and then running it (probably "as administrator", but I wouldn't know differently, as I am already the unique admin of the machine!).
The location for fetching the file is again
https://www.microsoft.com/en-us/wdsi/definitions
but in WD's case, it's the "Windows Defender in Windows 7 and Windows Vista" entries...
Have you noticed the "Windows Vista" mention? Unlike Windows XP, M$ have still kept file mpengine.dll (inside file mpas-fe.exe) Vista compatible, so they kinda "silently" have continued to support Vista even past its Extended Support EoS, so I was genuinely taken aback (and then miffed) they broke automatic updates for Vista's WD...
I have Vista SP2 Home Premium x86 (without the very recent ".6003" WS2008 updates) and hovering over the win32 link I see the following URI:
https://go.microsoft.com/fwlink/?LinkID=121721&clcid=0x409&arch=x86&eng=0.0.0.0&avdelta=0.0.0.0&asdelta=0.0.0.0&prod=925A3ACA-C353-458A-AC8D-A7E5EB378092
What's really weird is that clicking that link (during the last 2 weeks or so) has not always fetched the version claimed to be the latest in the page; e.g. the page may announce v1.299.301.0 as available, but downloading from the win32 link may get me an older version on disk (usually 3-6 "units" older, e.g. 1.299.296.0 etc.). To mitigate this, I have found the link in article
https://www.askvg.com/how-to-update-windows-defender-offline-install-latest-virus-definition-files-manually/
to be very reliable in faultlessly fetching the version advertised as the most current :
https://go.microsoft.com/fwlink/?linkid=70631
Alternatively, I would manually construct
https://definitionupdates.microsoft.com/download/DefinitionUpdates/VersionedSignatures/AM/1.xxx.xxx.0/x86/mpas-fe.exe
getting the "1.xxx.xxx.0" string from the downloads page...
@dencorso: Many thanks indeed for your .cmd file ; however, be advised you only considered the x86 flavour of the definitions update file; it won't do for MSE 64-bit, the preferred default on Vista x64 installations...
I also took the liberty of mimicking it for my own purposes, creating a WDUPD_Vista.cmd variant:
@echo off
::pushd %temp%
if not exist mpas-fe.exe start /min /wait wget -O mpas-fe.exe http://definitionupdates.microsoft.com/download/DefinitionUpdates/x86/mpas-fe.exe
if exist mpas-fe.exe start /min /wait mpas-fe.exe
del mpas-fe.exe
::popd
I commented out your second line, because that way one doesn't have to place wget.exe in the %PATH% variable, just leave it be adjacent to the .cmd file, both in a user writable directory! Again, this is for the 32-bit architecture only...
Thanks a bunch !