It appears that these utilities are "all the rage" as a large number of users are already benefiting from this easy solution as a reliable means to repair a rundll32 exe error and a variety of pc hassles. Useless registry keys can actually clog up and slow down the windows system and quite possibly the only way you can detect the obsolete keys is to let these utilities do the job for you. Something else you might want to try in order to stop these errors is updating your os files, with the result of purging glitches which are caused by old / corrupted files. When you come right down to it, your computer is really not much different from your car in that it needs looking after to keep it in the best shape possible. It's important to pay attention to your system's upkeep - should you fail to take care of it, i'm afraid you'll soon have a variety of hassles to worry about.