Definition updates of Microsoft Security Essentials for Windows XP listed on FAQ are older

[LEO33SoFo]

As listed on FAQ, Windows XP and Vista 32-bit Security Essentials (1.291.2489.0, 22 April 2019) is older than what I have (1.293.2807.0, 3 June 2019).

[kirb]

The April version is the last one I was able to find on Wayback Machine which ran on XP without throwing an error. Note that some later definition updates can be installed by patching them, but currently we don't host/link to any of those. (Might look into this at some point.)

Where did you find the June build? Maybe I could add it to that page.

[stdin82]

@kirb

mpengine.dll 1.1.15800.1 (Last XP/2k3 compatible)
x86
http://download.windowsupdate.com/c/msdownload/update/software/defu/2019/03/am_engine_8f724ad2cd892ac96c198a474c26b5286eb39968.exe
x64
http://download.windowsupdate.com/c/msdownload/update/software/defu/2019/03/am_engine_ca2920ce4bb8052a4a98db4a8f27b639a0fd782b.exe

mpavbase.vdm-mpasbase.vdm 1.293.0.0
x86
http://download.windowsupdate.com/c/msdownload/update/software/defu/2019/04/am_base_79107b9cc047ccd6baa10e27385f9814c89ed4ab.exe
x64
http://download.windowsupdate.com/c/msdownload/update/software/defu/2019/04/am_base_a784533fac63347bc6a80f1cdfdb863bac814de6.exe

mpavdlta.vdm-mpasdlta.vdm 1.293.2807.0
x86
http://download.windowsupdate.com/d/msdownload/update/software/defu/2019/06/am_delta_69bbd43267331aa1617813bda17a8ff191b35b21.exe
x64
http://download.windowsupdate.com/d/msdownload/update/software/defu/2019/06/am_delta_bf7269a04ae2ae352258673eb9c99784e2283066.exe

original mpam-fe.exe 1.293.2807.0 (not downloadable anyway) include mpengine.dll 1.1.15900.4, which isn't XP/2k3 compatible, due to using Thread Local Storage https://learn.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryw If you use this syntax in a DLL, you will not be able to load the DLL explicitly using LoadLibrary on versions of Windows prior to Windows Vista.

[LEO33SoFo]

@kirb I got it from MSFN forums years ago, from this file.