I've been having the same problems since I uninstalled Winamp. Every CCleaner scan of the registry showed "(.mp3, .mp4, .avi, ect.)/OpenWithProgids/Winamp" in my case. Each time I listen to music or watch a video the error returned in scans after previously being "fixed". So here's how to permanently fix this issue. When you uninstalled your program a registry entry was left behind. This entry in the registry tells the computer that the program is still on your PC and available to use for your media. Even though the program is no longer installed the registry still registers as if it is. You need to delete the registry entry manually. Open the registry editor by clicking the start button and typing "regedit". Select "HKEY_CURRENT_USER, Software, Microsoft, Windows, CurrentVersion, Explorer, FileExts". Select the most common media extensions that have been appearing in the registry cleaner and click on "OpenWithProgids". Right click on the uninstalled program name and select delete. Now I don't get anymore registry errors with any further scans. Problem solved. In my case I only had to do this with one extension and the uninstalled program was removed from all the extensions. But to be safe you should check all the extensions that have been appearing in the registry cleaner for you. Hope this helps.