All Windows OS systems, 98 and on, required a reinstall when you do major hardware reconstruction. Drivers conflict hell. Since all pre xp OS's have direct hardware access protocols (not Kernal/HAL access in XP which is why dos based games go down in flames in XP) is the explnaation for why your dos based games are toasty!!! Frankly, I'm surprised the OS loaded at all!!!
Noli Nothis Permittere Te Terere!!
EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.