Ok, basically on my old PC with the following specs:
- AMD Athlon 2700+
- MSI KT4V Motherboard (AC'97 onboard sound)
- 1.5GB RAM
- ATI Radeon 9000 series graphics card
- Windows XP Pro SP2 32-bit
- Acer AL707 17" Monitor
I used to be able to run Master of Magic, Tie Fighter, Zeliard, Civilization, Cyberdogs and other such games and applications from directly within windows without any problems.

However, I have now upgraded to a:
- Intel Q9450
- ASUS P5E Motherboard (SupremeFXII onboard sound)
- 4GB RAM (3.25GB available)
- nVidia GeForce 8800 GT (ASUS)
- Windows XP Pro SP3 32-bit
- Samsung 245B 24" Monitor
But when I try to run ANY of these games I get an "NTVDM CPU has encountered an illegal instruction" error. You can see the error messages as attachments below. Note that the Hex Code is different for each game, but doesn't change for the same game (ie every time I load say Zeliard, I always get the same Hex code). Interestingly, Civilization does actually load the start options (The select 1 for mouse and keyboard etc) in a small DOS window that can't be maximised or anything, but it then crashes with the same error when the actual game tries to load.

Google searching the error just seems to find people saying that this is caused by a virus, but that doesn't apply because I've got a brand new install and it happens on my brother's PC with the exact same specs (except a 19" Monitor).

Now I know NTVDM is the Windows NT Virtual DOS Machine, but surely this should still work right? I've tried replacing the version of ntvdm in system32, but it doesn't have any effect. My only thoughts are;
- Is this due to a lack of graphics support for DOS?
- Does my processor not support 16-bit instructions?
- Did something change in XP SP3?
(I doubt it's XP SP3 because I installed a new XP SP3 install into VMWare and it worked albeit it could not be maximised due to VMWare's graphics driver).

Yes I've gotten these games working in DOSBOX (VDMSound gives the same error), but I am dying to know why this is happening.