No amount of internal cleaning can get rid of the fact that a hacker has gained access to an E Mail account, nor can it stop it happening in the future.
Only a strong password can help prevent any hackers from stealing personal address books from E Mail accounts.
In most cases I have encountered, a change of password prevents the original hacker from regaining access to the address book, as these guys don't bother storing them for future re-use, why should they when they can access the account whenever they want till you change the password, it doesn't bother them when you do, they have hundreds more to play with to send their spam or other vile messages.

I will also strongly recommend not to use registry cleaners they can wreck a computer. What is the point of keeping a registry backup when the registry itself is so mangled it prevents you running the back up.
Three very good write ups about why registry cleaning is a waste of time any way.
http://www.whatthetech.com/2007/11/25/do-i-need-a-registry-cleaner/

http://www.edbott.com/weblog/2005/04/why-i-dont-use-registry-cleaners/

http://miekiemoes.blogspot.co.uk/2008/02/registry-cleaners-and-system-tweaking_13.html

C.Cleaner is a good cleaning tool, providing you do not use the registry cleaner, as shown above, pretty pointless and time wasting exercise any way.

I am not a moderator on several computer help forums for nothing, or because I don't know anything.