One word of advice when using CCleaner:
Ccleaner (Modifies registry – Always backup your registry before using)
(Prefetch Cleaning Warning - The Advanced section of Ccleaner has a performance degrading option to “clean Old Prefetch data", never select this option for cleaning as it will actually increase load times for Windows and your applications.
Cleaning the Prefetch folder as beneficial is a Myth and actually degrades performance. Windows by default cleans this folder at 128 entries. Anyone who claims this should be cleaned for ANY reason does not understand how Windows Prefetching works.) http://www.ccleaner.com/
In addition, always backup your registry before making any changes or using any program that makes changes to the registry.
There is a freeware program named Erunt that will automate registry backups at intervals set by you. Highly recommended!