A Google search for: 

"fix my computer"

tells me to use a Registry Cleaner!

           What is a Registry Cleaner, Heck what is a Registry?

A real simple explanation is that it is a long list of all hardware, software and data files stored in your computer.

The operating system (ie Windows XP, or Windows 7 etc) looks at the Registry every time you do something, such as:

1. Starting the computer;

2. When installing / uninstalling a program;

3. Creating a document;

4. Recording the last web site you visited and much more.

One of the many issues which can cause a corrupt or bloated Registry is the poor uninstallation routines (software) which actually uninstall software. Quite often they will leave empty Registry entries, or entries which still have the relevant information for the software (which is now gone).

A bloated or unstable Registry can slow down or even stop a computer, and worse still it can actually stop the PC from starting! There is a significant risk to your information if the Registry is corrupt.

With the Registry recording so much information, making the slightest change to it can cause a severe problem if done incorrectly. I have edited the Registry manually, as have many other technicians, but by far the safest, quickest and easiest way to do this is to use a Registry cleaner.

There are many Registry cleaners available, most of which do a fine job at cleaning and maintaining your Registry, temporary files and other security issues (spyware in particular).

Please ensure that you use a quality Registry cleaner, one that you know works, that is reliable and is proven

Finally, if your Registry becomes corrupt the chances of the computer not starting are quite high, did you do a backup?