>Does it really speed up computers?
No, not really. Even if it did, it would be far less than 1%
>the scan results said I have over 800 errors
Well if it said you had no errors you would not buy it !!!
These sort of scans always say you have hundreds of errors so you rush out and buy the product.
Like ACtheTroll, I think most registry cleaners are a con and do almost nothing of benefit.
I have been using PCs for years and never felt the need to run any sort of registry cleaner.
And as other have said, the registry is one of the most important fles on your computer, and a bad registry cleaner could well delete entries from it and stop your computer working.
If your computer is running slow find some other way of speeding it up, not a registry cleaner.