I have a Compaq Deskpro EN, P3 1Ghz, 512 MB RAM, with integrated intel 815 gpu + Nvidia GeForce MX 4000. Windows 98SE.
Without this card, everything works fine, but when I insert it I get this Windows Protection Error. Restart your computer.

I saw similar posts like this, but all of them are if you have > 512 MB of RAM. I have exactly 512 MB one module.
- Memtest is ok
- Tried latest nvidia drivers + one older downloaded from vogons
- Tried unofficial SP3 for Win98
- Tried setting those two parameters (forgot the name) in system.ini

What else can I try?

P.S. System + all drivers were installed first and then I put this nvidia card and installed drivers for it