Avast causing problems with DOS programs on XP???

Avast Free Antivirus / Premium Security
1

I just did a clean install of XP Pro SP3 on a new PC with an AMD LE-1260 CPU and 2 gigs RAM. There cannot be any viruses or malware on it, I’ve installed nothing but Windows, IE8, Media Player 11, Adobe Reader 9, WinZip 8.1, the latest Firefox (non-beta!), Google Chrome, all current updates from Microsoft Update, Avast 4 and Spybot S&D.

All fresh downloads, not from anything that’s been in contact with any other computer.

So now I want to run an old EGA solitaire card game that’s never ever had any problem running on any PC all the way back to an IBM model 5150 PC, or on any version of Windows from 3.1 through Vista Ultimate.

When I run it I get “The NTVDM CPU has encountered an illegal instruction”. Searching the web shows that’s an issue with the 16bit MS DOS Subsystem.

Why I’m wondering if Avast might have something to do with this is http://support.microsoft.com/default.aspx?scid=kb;en-us;Q314452

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\VirtualDeviceDrivers\VDD

has C:\Program Files\Alwil Software\Avast4\aswMonVd.dll in it. The COMMAND.COM in the System32 folder is the correct one.

A post on another forum claimed adding the full path to COMMAND.COM in config.nt fixed this error. shell=c:\windows\system32\command.com /e:2048 /p
Didn’t on this computer.

2

If you have had Norton in this computer, the VDD key could be corrupted.
Maybe some other program is corrupting it.
Maybe you can follow: http://forum.avast.com/index.php?topic=707 or http://forum.avast.com/index.php?topic=259

3

I don’t let Norton or Symantec software near my computers.

I only installed Avast with the Standard Shield. It didn’t change anything in config.nt, I’m not running the bootup scan. This old DOS game has always worked before with Avast installed.

4

Ok, but some program could have corrupt the VDD key with two groups of zeros 00,00

5

This is what’s in that VDD key

C:\Program Files\Alwil Software\Avast4\aswMonVd.dll

I did a boot scan with Avast and it found nothing. Looks like Avast boogered the VDD key instead of leaving it alone and sticking the path to aswMonVd.dll somewhere else.