I am using a Toshiba Laptop with windows xp home EDITION 2002. 0.99GB of RAM. I have two accounts on this laptop. A "guest" account which I rarely use and then my main account which requires a password and has admin privileges. The other day I noticed every time I tried opening Mozilla, my whole computer would FREEZE up and nothing would happen. So I would turn the computer off and log back on and use internet explorer instead. The next time I logged-in to my admin account the desktop loaded fine except the bottom tool bar and start menu. Then I got a NOTICE "windows explorer has encountered a problem and needs to close" This is what came up when I clicked on the tech. support:

C:\DOCUME~1\Beckyy\LOCALS~1\Temp\WER0384.diroo\explorer.exe.mdmp
&
C:\DOCUME~1\Beckyy\LOCALS~1\Temp\WER0384.diroo\appcompat.txt

I hadn't tried installing anything before this occurred and haven't really gone to any websites that I've never been to before. Please help. I'm not sure how I can do a system reboot or reset since I can't access my start menu. When I go on my "guest" account none of this pops up and there seems to be no problem but since the guest account doesn't have admin privileges I can't do any rebooting from there. Last night I downloaded AVG Anti-Virus scan. Not very computer savvy. CTRL+ALT+DEL to open Task Manager, click on "New task" button, type in:
sfc /scannow
Click OK.
Have Windows CD handy.
If System File Checker (sfc) will find any ERRORS, it may ask you for the CD/DVD.
If sfc won't find any errors in Windows XP, it'll simply quit, without any message.
Thank you for your help. However, the sfc/ scannow was not recognized and then the computer started slowing down and froze up. Not sure what to do now. I have a feeling it has something to do with internet explorer. Under the processes running there wasn't much up but explorer.exe was and I didn't have internet explorer open and it was using about 17,000 KIt looks like you have SERIOUS system files corruption.
Try repair: http://www.michaelstevenstech.com/XPrepairinstall.htm