[Mark McLeod]

Don't replace parts if they aren't causing a problem.
Try the simple things first.

Is your power meter showing problems?
Very low battery reserve will cause the Classmate to operate very, very slowly, as in click and wait 10 minutes for the action to complete.
That could be caused by a damaged battery that's easy to replace, but it'll show as red in the battery meter if that's an issue.

I've seen netbooks with bad sectors on the Classmate Flash drive clobbering the operating system, such that it has to be reinstalled.

Memory card can be reseated easily if it's a recurring memory fault killing your machine.