Did you try a system restore point? It makes changes to the registry, hopefully you have a restore point to go back to. I don't like paying for removal tools, and so far the only information I have found it paid for items. There has to be a quick fix for something like this.
Any theme type program that makes changes to the registry or windows itself other than the windows shell should be avoided at all costs unless you know what your doing as you've found out,there's only two programs i know of apart from winstep & they are windowblinds & desktopx which are part of object desktop suite,if you want to customize then od suite is the one to go for it won't make deep changes to windows OS,any changes made are easily undone simply by unloading the applied theme edit:steer clear of pirated windowblinds & desktopx if you know whats good for you otherwise your on your own