Windows XP is the most stable version of Windows yet. But many users, particularly those coming from Windows 98 and ME aren't aware of many of the built in features that allow users to recover from almost any problem.
Here is a short sample:
Any time something hangs, you can hit
Ctrl-Shift-Esc to bring up the task list. Often times, what is hung won't report itself as being hung. Here are common process names you can kill to get your desktop back to normal:
IEXPLORE.EXE (IE)
explorer.exe (Explorer)
msimn.exe (Outlook Express)
Pretty much these 3 are the ones that tend to cause problems.
Then there's the overall performance. Make sure nothing is eating up your CPU. If you're at 100% CPU (click on the performance tab) then find out what is doing that. Back at the processes tab you can sort by CPU usage by clickin gon the "CPU" header. Find out what's eating all your CPU and kill it.
Next comes general stability. There are 3 things that can cause Windows XP to get flakey:
1) Too much memory used will make the system sluggish
2) Too many GDI objects will eventually make the system very slow and cause buttons and such not to show up
3) Too many handles will do the same thing as #2.
But how to find this out? On the processes page go to the view menu item an choose "select columns". Look for GDI objects and handles. Then start sorting by them. Anything using more htan 1000 of these things is probably bad news. You may want to add user objects while you're at it and see if anything is sucking them up.
Look also at how much VM size things are using. For instance, as I type this Explorer is using 95 MEGABYTES of VM. Now if I wasn't using the Task manager I wouldn't think anything of it other than my system be slower than it should (in fairness, I run my system for weeks at a time so things build up). So I'll be killing explorer to refresh it back. Incidentally it was also using over 3000 GDI objects and 2500 user objects and 2000 handles. So it was definitely a drain on my system.
You can reload explorer by going to file New task and type in "explorer" and it will restart it. Now it's only using 11 megs of VM and 228 GDI objects and my system is fast again.
The key though is to use Ctrl-Shift-Esc rather than Ctrl-Alt-Del to get to the task list where you can perform recovery techniques to avoid having to logoff or reboot.
Feel free to add more tips here.