It will test your RAM. It sounds like you have hardware problems, so these are the two things which Users can test most easily.
If you have bad RAM, isolate which stick is causing the errors and replace it.
If it is the HD, sometimes the maker's repair scan can fix the HD to return it to normal service, or you will know for sure it is the problem.
If the hardware is clear then I would wipe the HD to reinstall Windows 7. Free Partition Wizard bootable CD will autostart to wipe your HD with zeroes to overwrite any possibly infected code. Then the Windows 7 DVD should autostart, too, to reinstall. Partition Wizard : Use the Bootable CD
If you have a factory Recovery partition, you can also run it from boot: http://support.dell.com/support/topi...7D4&doclang=en
If you can't boot the DVD to copy out your files using this method Copy & Paste - in Windows Recovery Console
then use Paragon Rescue Disk which should autostart to rescue your files: http://www.paragon-software.com/home/rk-express/
I uploaded the best image burner. Use 4x speed - it never fails: