Windows 7: Restore point error

When I go to restore point it gives me the following error: %systemroot%\registration
I know a lot of people have this problem, I have been on the computer for over 2 hours reading all of it and nobody being able to fix it.
The reason I want to reset my computer to an earlier time is because I went to a website that told me how to optimize my computer. So I did what they said and now my computer is acting weird. (this site was given to me on these forums!!). I want to go back to before I optimized it and I can only do this from a restore point. I do backup my files on an external hard drive - but that won't work here.
Hope someone can help. Thanks.

What is the website you refer to??

Speed Up Windows 7 - Ultimate Guide To Make Windows 7 Blazing Fast!!!

and this one: Speed Up Windows 7 – Master Tutorial to Make Windows 7 Super Fast - Tweaking with Vishal

I don't think I did everything it said to do, especially if I had no idea what it was!

What have you already tried to fix this?

Specifically: have you investigated what "services" are running on your PC?

Have you run sfc /scannow from a command prompt?

I have googled this error and they were from 2009 or so, and they had me type in services and make sure shadow something was on automatic and also system restore. But I didn't have a system restore. They also said something about an administrator, but I was. There was just a list of things to check and uncheck so I did.
I have run scannow, but I am not sure what you mean from a command prompt. I just did it from a regular boot.

This problem bothers me since so many people have this problem and they haven't found answers. It makes me think it is unfixable. I tried to email Windows, but you had to pay for that and I didn't want to do that.

Is command prompt on the black screen? If so, how do I get there and how is it different than doing it from a regular boot? Boy, I am full of questions, aren't I?

Looking back on previous posts, the restore point didn't work before I optimized my computer