What version is your Mscan32.dll?
(please note the spelling of the filename: McScan32.dll)
3,182,712 . 07-31-09 . 6:40a Mcscan32.dll
File Properties | Version (under WinXP) ... v5.400.0.1158
File Properties | Version (under Win9x) ... v5.4.00
CRC in WinZip ... c2482d68
MORE INFORMATION ... I was able to search through a collection of McAfee DATs and determined that this file (McScan32.dll) has been identical since around the 5741 release circa 2009 September. In other words this file has been unchanged for almost two years.
SUPPOSITION ... at some point this DLL will again be changed and will likely not work with Win9x any longer even though the 10 year old executables will function as always. The question will likely become, will the DAT files of some future time work with an older McScan32.dll on Win9x? Your guess is as good as mine.
None of this would be necessary if all the antivirus vendors and virus research labs simply agreed on a standard DAT database while keeping their engines and applications proprietary. But that would be just too logical.
Does anyone have access to 5100eng9x.exe?
I couldn't find the 5100 DATs on any hard drives I have stored. But I did see 5090 and 5110. McScan32.dll is identical in both of those releases ...
2,867,438 . 06-09-06 . 5:10a Mcscan32.dll
File Properties | Version (under WinXP) ... v188.8.131.52
File Properties | Version (under Win9x) ... v5.1.00 (probably)
CRC in WinZip ... ca1d76ed