[SixOfSpades]

One of the big causes of programs slowing down or locking up is other programs running "in the background." Try it now: If you're running Windows, Press Ctrl-Alt-Delete ONCE, and a window will pop up, showing all the programs that are running at the moment. Some of these are programs that you can see, like Internet Explorer and (if you've got it minimized) Baldur's Gate. Other programs are part of your operating system: Explorer and Systray are vital for Windows to keep working, for example.

The BAD programs on this list are those that are "Not Responding." They're locked up, but they haven't told Windows that they've screwed up, so Windows doesn't know what to do with them. They're still running, and Windows is running in circles trying to figure out what to do with them, and all of these processes eat up RAM that you'd much rather put to more useful purposes--like animating several spell effects at the same time without slowing down the computer.

If any program or programs are "repeat offenders" on the Not Responding list, consider moving them to a different directory to see if they actually DO anything, and if they don't, you'd probably be better off deleting them entirely.