I have a 2003 Inspiron 5100 and it has been running incredibly slow for the past few days and it started after the I run an offline optimization at startup. I was doing that because the computer has been doing all sorts weird stuff such as not being able to go into standby, monitor goes completely black and not respond to any commend, spontaneously shut down when I switch from battery to AC adapter etc. All of these weird things seem to intermittently (except the last one which hasn't happened for a whiled now). I have ZoneAlarm and Spyware Doctor running all the time and do regular scan and updates all the time. I also perform defragmentation and registry check too. Nothing seems to help. I run a full hardware dignostics and it found nothing wrong with the harddrive. I am really at a lost as what to do to fix the speed problem.

I have 512 MB memory and according to Norton System Works it is 58% utilized which shouldn't be a problem. I don't think. Anything I can do to figure out what's wrong with this computer? It is really driving me insane! Any help will be greatly appreciated!!

Jing