then clean your registry.
Bleeping Computer
DOES NOT recommend the use of registry cleaners/optimizers for a several reasons:

Registry cleaners can damage the registry by using aggressive cleaning routines. Many users (including some Staff Members) have reported problems after using registry cleaning tools - to include those tools released by Microsoft. This can cause your system to become unbootable.

Registry cleaners generally don't do anything significant for your system. This topic discusses it in greater detail than we could address here:
http://www.windowsbbs.com/showthread.php?t=61015 Although the topic discusses the XP registry, the concepts there apply to all other versions of Windows.

Not all registry cleaners create a backup of your registry before making changes. If the changes prevent the system from booting/logging in, then there's no backup to restore in order to regain functionality. A backup of the registry is essential
BEFORE making any changes to the registry.
I managed to destroy my Adobe Photoshop program by using a registry cleaner. I had to reinstall the program. Fortunately, that was the worst that happened in this case.
Orange Blossom