In addition to automatic cleaning, which offers a variety of programs and utilities, there is a manual registry cleaning. Choose clean manually only if you are an experienced PC user and confident in their knowledge and skills. Illiterate working with registry can lead to serious consequences including system failure — so grab the cleaning manually only in extreme cases, being self-confident.
Go to start and choose Run. In the open line, type regedit and press enter. A window will open with the registry editor, where you will see a column of folders and parameters. Under "My computer" locate the sub-folder HKEY_CURRENT_USER and go to the subkey Software.
Find records of software that you once stood but has been removed. Entries remained in the registry and prevent system operation. Remove superfluous records.
Then open the HKEY_LOCAL_MACHINE sub-folder and open there the same partition (Software). Again find all files on remote programs. Remove them.
To accelerate and improve the work system, that's enough — apply the changes, shut down the registry editor and reboot.
If you want a more deep and serious cleaning up of the registry, use Ccleaner or RegistryBooster. They eliminate the errors in the registry on a deep enough level and make a backup before making changes — in case of failure, you can restore a previous version of registry, which is not possible with manual cleaning.