Hello 2 weeks ago I decided to clean up my computer a bit. I scanned for viruses, malware,etc and cleaned the registry with CCleaner. This time I didn't make a backup of my registry. When the cleanup was done, my computer rebooted at the same second. (Seems like I deleted some vital stuff from registry.) The computer still powered up as normal, and works nearly the same as always. But, now 2 weeks later I got back to my computer and turned this on. After I had logged on windows I turned my external hard drive on and noticed that my computer couldn't access it. It does show in Device Manager, but I can't access it. Same thing happens with every USB Mass Storage Device I use. Memory Sticks, Memory Cards, PSP etc. When I plug memory sticks or memory cards in my PC, they do show up in My Computer. But when I click on them, i get the message that they need to be formatted. If I plug the devices in my computer before I turn it on, the USB Devices work the way they should. But the problem gets irritating when I need to reboot my computer every time I want to use external hardware. Any suggestions? Any solutions? I have a registry backup that is about 9 months old, since I haven't been using my computer much since. Should I add the data to the registry, or is there a possibilty something irreversable might happen. The problem doesn't seem to be caused by malware or viruses. Seems more like problem with registry. I'm using Windows XP Service Pack 3.