SO this is mind blowing....I installed my ancient AGP 8X 7600 GS graphics card (512 ddr2 ram) and it runs like a dream!!! Not only can this dog of a PC play HD video without a hitch, I can play Dead Space on Medium settings and it runs perfectly!!!! Windows 7 FTW!!!
Here are the specs of this ancient PC:
Pentium 4 with HyperThreading Technology
1 GB of DDR Ram
160 GB EIDE Hard Drive
Nvidia 7600 GS 512MB video card (8X AGP)
DVD-ROM drive