Yes i am not surprised on older machines Win 7 could be causing the problem. The title though does make people believe you mean all of Win 7 (trust me all people won't read your entire post).
I have a good machine that i went all out on so its up to date. I run win 7 64-bit with 2x monitors and run this game full high without issues since its not out to date.
i7-2600k
2x SSD in raid 0
8GB DDR3
2x GTX 580 in SLI
But all in all .. out of date = harder to run on the latest hardware. Nothing new.