1. Download and install a free registry cleaner such as RegCleaner, CCleaner or Registry Mechanic (see “Resources”). These programs will scan your registry for outdated or useless entries, removing them in the process.
2. Open the registry cleaning program and select the 'Clean Registry' button to begin the cleaning process. Depending on the speed of your computer and the size of your registry, this can take anywhere from 30 seconds to several minutes.

3. Click on the 'Fix Problems' button to delete redundant or outdated registry entries found by the cleaning program. This will speed up your computer and fix stack overflow errors.