Windows 7: Dell laptop trouble restoring to factory image

Hi,
Ive owned a dell studio 1558 laptop for almost 2 years now and have recently been experiencing some overheating issues, among my many solutions "new thermal paste, cleaning the inside" and a virus scan using Avast, which discovered a four digit number of corrupted files followed by their deletion and subsequent problems due to now missing some .dll files making me unable to run anything or access the internet. Ive decided I should restore the laptop to its factory settings which I believe I have done before. The problem now is that once I reach the Advance boot menu using F8, I press enter on the "repair your computer" option which is followed by a bar saying windows is loading files, lasting one second, and then windows loads up and nothing changed. Any suggestions would be greatly appreciated thanks.

David,
Welcome to SevenForums.

Did you create the Factory Restore discs? Yes/No.

Thanks,
No I have no backups and no dell/win cds, never came with the laptop. I was always under the impression that there was a backup built in and would resort to that.

Pity that you didn't read the documentation that came with your computer.

Now with that said:
You are very fortunate that you have a DELL. They have excellent support for you.

https://support.dell.com/support/top.../backupcd_form

That's the specific info. Here's a link which also explains the DELL procedure.
Lost your Windows discs? How to get replacement media, legally | ZDNet