Make sure you know what you're doing before you change operating systems.
Windows NT is not just a "more stable kind of Windows 98", or anything like that. It is a very different operating system, not targeted for home users. I personally wouldn't put NT on a recording computer unless I used that computer for recording, and nothing but.
But yeah. I've experienced Cakewalk crashes in Win98 too, and it pisses me off. In fact, I'm fresh off an extremely annoying crash right now. This message board is good for soothing those raw nerves.
But I'm not sure you can blame Windows 98 for that. In my case, anyway. It was Cakewalk that crashed, not the Program Manager or Explorer (the most common Win98 crashes). Would that problem be eliminated in WinNT? I don't know; I've never tried it!
For those of you who have LOTS of crashes in Win98, it may be time for a clean install of Windows. Yes, it's a pain in the ass. But after a clean install you'll have hard drive space you didn't even know you'd lost, your computer will run loads faster, and Windows will crash far less. Windows 95 was far worse, but Windows is still a self-corrupting operating system. The longer you use an installation, the worse things become.
You can counteract this if you know enough about your computer to do routine cleanings and tweakings. But I've been working with computers for about 17+ years now and even I can't keep an installation of Windows running forever.
Some people have it far worse. I've seen people with very fast computers, whose machines operated with about the speed of a 486 - when they operated at all - because those people cluttered their Windows installation to the point where it was beyond repair.
Now, if you don't have backup capabilities, this is pretty tough to pull off. But if you do, wiping your hard drive clean and starting over is more painless than you might think. And assuming you have a quality machine to begin with, it can solve a host of problems.
Spider mentioned performance issues even with 256mb of RAM. If you're running Windows 98, anything more than 128mb is practically useless. It's far more likely that the bottleneck you're experiencing is your CPU or hard drive.
I've read that 256mb may help performance in Win2000 and NT, though. Can anyone vouch for this?