Jhill,
You need to realize that neither Win98 nor WinMe is terribly robust. Any application, device driver, just about any software on the machine can cause incredible instability.
With the NT/W2K/XP architecture, things are very different. Under the NT kernel, the OS has far greater control over the machine and what apps can and cannot do. (That's not to say that apps and drivers can't still take down the system, it just requires a lot more effort.)
I agree with others: the instability is very likely to be some piece of software you are running, rather than the OS itself. Start uninstalling useless junk that's bloating your system (if there is any) as a first line of defense.
To really get stability, though, you're going to have to give up on the Win9x line of operating systems.
-Noggin