Smart people may debate whether or not you should use a registry cleaner. Some people swear by them; others warn you to stay away from them. But whichever side of that debate you fall on, it is certainly true that during normal Windows operation, data is constantly being written to and deleted from the registry. Over time, just like the rest of your drive, the data in the registry becomes fragmented. So those fragments and wasted space in the registry need to be cleaned up to improve your system's performance. Some have even put together "special" utilities to defragment the registry. But PerfectDisk can move the registry hives online, so when you're defrgmenting your entire drive with PerfectDisk, you're defragmenting your registry.
Why is this woman smiling? Looks to me like she's just had her registry defragmented.