I started having this problem after using DVDdecrypter. I noticed significant CPU usage until cursor stops responding to input and then I got the low Virtual Memory caution message. I've used msconfig to clear out unnecessary bootup programs to no avail. I've used CCleaner, ad-aware, spybot etc... Now when I boot up, i'll see the cursor, with b/g, but no icon, no start menu. I have to wait about a minute before my ctr+del+atl would bring up the task manager. however I don't see any suspicious process is running. When i tried to logoff user, i'd get a message about explorer.exe stops responding, so I have to interrupt and end the program manually. After re-login, it will bring back all icons, start menu, though I notice the computer is still slower than before. Any help is much appreciated!