Troubles Bubbles?? Why yes, yes i am.

Two years ago I killed my computer with the lovely cocktail of downloading a bad file that I jut had to have whilst the McAfee system that came with the computer went to war with Avast. So I didn't start on the right foot. Thus I come to everyone and anyone willing to help looking for an answer I cannot find myself.
I have a Dell Inspiron with Windows 7 model PP41L; needless to say it has crashed.:cry I have the discs that came with it and I so desperately want to reformat it to its factory settings. I've tried pushing F8 on the dell icon along with ctl-F11... to no avail it is not doing anything differently. When it starts up it does an automatic system repair and it never works; so i've disabled it. I am currently running a memory diagnostic. I have little faith it will work seeing as this is the 50th time i've tried it. Though the first since the disable. If it happens to go to the same ol' options it gives me I would have tried everything I could think of. Now this screen it always brings me to lists these options: system repair, system image repair, System memory diagnostic, command propt, and dell datasafe. Please Help Me!!!