You'll need the correct bit-version installer or Repair CD to run System Recovery Options
if it will not boot from the F8 Advanced Boot Tools menu.
I'd try also running Dell Diagnostics from boot.
Use the Repair console Command Line to run Disk Check
and boot the HD maker's HD Diagnostic
extended CD scan to attempt to repair HD.
You can copy out your files using Windows 7 DVD, Repair CD or F8 Repair console using this method: Copy & Paste - in Windows Recovery Console
Next you can try running the Factory Recovery from boot: Dell Restoring Your Computer´s Software to the Factory Settings
Or you can use a Windows 7 installation DVD to clean reinstall following these steps to get a perfect Factory OEM Clean Reinstall: Reinstalling Windows 7