You need to post in one of the Windows Forums, they are better equipped to help you restore your system. They can run you through restoring your system back to the factory defaults, hang on to those disks, you will need them. Another option is to call Acer Tech support and tell them that you messed up your registry and that you need help restoring your computer back to the factory defaults, keep in mind that you may lose your programs and any documents so you need to back up any photos or documents that you dont want to loose first. The best way for that is to buy a thumb drive, you can pick one up at Costco real cheap and all you do is copy and paste any files you want to keep to your thumb drive.
Ken