How can I fix my desk top?

Looks like you are missing some vital Windows' file(s).

Get a Linux Live CD and boot with it.
Use the Linux environment to backup your data to some external support(s): Cd, DVD or USB storage.

If you can't backup.
Temporarily unplug the original drive.
Get a new hard drive and install it. Plug it on the connector that was used by the original drive.
Install Windows on the new drive.
Reconnect the old drive. It's now your D:\ drive. ALL your files are safe on it. You can delete the original Windows folder as it's no longer used in any way.

Installing on a new drive normaly don't allow you to do a restore to factory default, as this process uses a hiden partition holding an image of your original boot drive. That hiden partition obviously don't exist on a new drive.

You may need to reinstall Windows, it's a process that can irrevocably destroy your data.

Once you've reinstalled Windows.
If you restored to "factory state", you NEED to uninstall all the packaged junk FIRST!!!

Reinstall your drivers, starting with the video drivers. It may have beed done with a restore. Anyway, check if they can be updated.

Next, reinstall your applications.

Finaly, get your backed up data.

Electro
August 2011