Windows 7 Stuck in diagnostic loop

I have windows 7 home premium 64bit. My dell laptop is currently stuck at the diagnostic startup whenever I load up the computer. I have ran both memory test and memory system, and both indicated no error. I have tried going into safe mode using F8 but that didn't work. I tried reinstalling the system using my Windows 7 CD but apparently I can't boot from the CD either. The CD doesn't automatically read nor does it work from the F12 boot up. I can't access the command prompt either. No matter what I do, it keep returning to the diagnostic screen.

Please help!

Sorry, I for the tests, I meant Test Memory and Test System, both of which I ran and had no errors.

This is the screen I get everytime.

I can't go into either.

Kaktussoft said:

lostlimit said:

I can't go into either.

Can't you enter the BIOS? Can you boot from installation DVD?

Nope.

Kaktussoft said:

Did you read the manual how to enter bios? did you read manual how to set "boot device order"?
Did you ever before bot from cd/dvd or enter bios?

Yes, i know how to enter bios and boot from cd as i have stated in my first post. But none of those worked.