You don't provide enough information to get good advice. It could be
software or hardware related. I'm not sure what the last poster means
by telling you that you need to "max out your RAM". Having a lot of RAM
is good, but that's not addressing your problem. Here are generic
troubleshooting steps for the software end of things:
1) scan with current antivirus using updated definitions; 2) remove
spyware with tools such as Spybot S&D (
www.security.kolla.de) and/or
Ad-aware (
www.lavasoftusa.com) - note that it is a good idea to do
virus and spyware scans in Safe Mode; 3) delete temporary and Temporary
Internet Files; 4) stop unnecessary services/programs from running at
startup (see
www.blackviper.com for a listing of services). Also, look
in Event Viewer for clues.
For the hardware end, start with a RAM test - I like Memtest86. Then
move on to hard drive and motherboard tests.
Malke