Registry cleaning software is not perfect, sometimes it takes out something that seems to mess our PCs up even more.
I know that this is an old question, but here's a possible answer for future viewers:
Restore the previous registry cleaning(s). In some cases, this'll restore functionality to whatever is now "broken", and then you can remove the registry cleaner at that point, should you want to.
I've never used RegCure, but I know that it's very, very popular due to the heavy marketing. Take any registry cleaner on the market, and you're going to have people saying that it broke their PC. RegCure isn't any different -- some people love it, others hate it.
Here's a link to show you on a popular, but free, registry cleaner:
Registry cleaning is a very, very touchy process. Only use registry cleaners that have a built-in, easy-to-access backup option, and if something messes up that you need -- restore your previous cleanings.