Registry cleaner thingy?? No disk to restore? Um I would say time to buy a new version of windows. Unless someone else wants to give this a shot? No im not making fun of the registry cleaner thingy. Be nice to know what cleaner you used though. Task manager to get on the net?? In windows 2000 which I know little about is that even possible??....peace....im out

Did you backup the registry before you used the cleaner? If so, you can restore it from that. If you didn't, here's how to do it (for future reference):

Go to Start, Run, and type in regedit; click OK and the Registry Editor will open.

Before you edit the registry, you should make a backup. At the top of the Registry window, click on the Registry menu, click Export Registry File. In the Export range panel, click All, then save your registry as Backup.

Make the changes you want, then exit the Registry Editor. Or, if you're just making a backup, Exit without making any changes.

get registry repair tool for win2000
HERE