How to Manually Clean Your Windows Registry

1. Detect registry problems in your computer. It is important to detect registry errors, because it helps you identify the main source of the problem. Look for the common signs of registry errors---which are: decrease in computer performance, frequent computer crashes, and frequent .exe and .DLL errors. You can also use a registry scanner to look for registry errors.
2. Open the Registry Editor. The Registry Editor allows you to modify and remove registry settings. To open the Registry Editor on Windows XP, go to the Start Menu, and click on 'run'---which is located at the right side of the Start Menu. To Open the Registry Editor on Windows Vista or Seven, access the Start Menu, and type 'regedit' on the search bar.
3. Edit and modify registry settings. After Opening the Registry Editor, go to 'HKEY_CURRENT_USER' and select 'Software'. You will then see a list of the registry settings for all of the software on your computer. Remove registry settings of programs that already uninstalled from your computer. Old traces and settings of a program are usually left behind, after it has been removed. To delete a registry file, simply right-click on it, and click on 'delete'.