[Edi]

Another thing I thought of was: What language and display support do you have enabled? I have almost everything and never had problems.

It could be the model difference. Also, if you installed some DirectX stuff from other games instead of using the MS DirectX installer, I suppose that could cause some trouble.

As far as Ccleaner goes, you can generally trust that registry tool. I have never seen it remove anything other than references to things that aren't there anymore.

I hope you get your issue sorted out.