"a huge leap forward from Windows 9x"
That is very true.
Windows 98 SE, as fun as it was, couldn't run more than 24 hours without borking itself. Windows XP, especially in its 3rd edition, was better on that point, even though it took Windows 7 to convince me that Borkzilla could actually write an OS that didn't continually trip over its own feet.
That said, even with XP I had to reinstall from scratch every now and then, just to have a system that appeared to run smoothly. Between my computers and my friends' computers, I reinstalled XP over 300 times (yes, I counted).
Windows 7 was a true breath of fresh air on that point.
Biting the hand that feeds IT
