Windows XP Pro, Major Performance issues

Greetings to all.  I have a Dell Vostro 1000 running Windows XP Professional, IE8, 2 gb of Ram.  Last Tuesday,  I went from a nice little machine to one with problems.  First, I was unable to access my USB Flashdrives.  I could plug them into other machines and they ran fine.  When plugged into the Laptop, I could see the light on the drive flashing, and if I went into Device Manager and looked at the Hard Drives, it was there.  I tried a shutdown and reboot.  Shutdown took over 1 hour.  When I rebooted, everything semed fine until I plugged in the flashdrive.  This time my Browser started giving me a "Not Responding" message.  If I waited long enough, sometimes it would come back to me.  If I tried shutting it down, I would get the request to send the error message to Microsoft, which I do, but the Window would still not shut.  I ran Microsoft Defender, AdAware LavaSoft and Avast AntiVirus packages, several times.  Nothing.  I was getting the same problems with other browsers as well.  I finally bit the bullet this weekend and did a complete reinstall, from the Dell disk.  I have not plugged in a flash drive yet, but the problem with IE has returned

If you need any information that I might have left out, please ask

Any suggestions, comments or feedback would be greatfully appreciated.