Sometimes it is difficult to uninstall software cleanly from add/remove programs. It doesn’t clean registry and leftover files/folders. This prevents from installing new software or work new program properly.

Shareware software, Revo is one good software to clean program and able to trace registry settings, files associated with program. Instead of manually cleaning registry settings, it is worth to try with 30 days free trial.

http://www.revouninstaller.com/