Oh, very-very common issue in times of Win98 and XP for me. Not because this Windowses are buggy, but because interaction between Windows and "Starforce" disc protection overpopular in Russia at this times. See, it make itself middle layer driver between core and "true" CD/DVD drivers. And it rely upon "bad/weak" sectors. Everything is allright, until you'll encounter
really bad CD. Sum of Starforce efforts to read it and Windows efforts to minimize problems ends in system falling back to safest - PIO - settings too frequent.
Moreover, seems, bugs in earlier Starforce drivers sometimes resulting in PIO settings for your
HDD - and it's
much worse than CD hassle! (Cure is the same - delete device and let Windows to re-found it for you).
Also, you don't need to reload whole system. Button "scan for new devices" will work it out.