I know the difference between the two processors were hugely apparent early in the release of Celeron processors, but I was under the impression that many of the drawbacks of Celeron had been overcome...especially recently. Over the last few months, I've been replacing all the PC's in my office. About 20 machines total. All of the machines that are used constantly at people's desks and in their office, I used P4 machines. I beleive 2.8ghz. They run great...haven't had the first problem from them. 4 of the machines I opted for Celeron. I think these run at 2.6 ghz. These are used at our sales counter and basically all they run is a UNIX emulator (Tiny TERM) for access to our main program, occasional internet useage (via Mozilla) and a couple of databases. One is a small Windows program and the other is an old DOS based program that runs in shell. None of these programs are taxing or require much in the way of resources. When I first set these systems up, they ran great. I noticed that they booted a bit slower than the P4's, but it was a very small difference. But now that they've been installed for a few months, they take forever to do the smallest things. I reboot them at least weekly (which is now a 3 - 5 minute process on all of them), but after running for a while, simply navigating Firefox is a jerky, studdering process. Scrolling down line by line on a database takes 2 or 3 seconds per click to register. The emulator runs fine but that's because the PC isn't really doing anything. Is this just the difference between Pentium and Celeron, or could there be something else here? I'm not really thinking virus or spyware because all 4 are acting the same way, plus I have them locked down pretty tight as far as access goes. Just curious so I won't repeat this in the future.