My kid has a a 5 year old Companq desktop with an early model Nvidia 8800 in it. It has a somewhat upgraded PS from Thermal Take. If I was interested in just replacing the video card would any modern card that would fit in the PCI-E slot work?
What’s a good card for less $ 125?
Yes, but you need to check the power requirements against your power supply. This card is pretty popular.
Assuming power requirements are met, yes.