Just a thought, based on previous experience of similar problems, it is possible that your system disk file structure is corrupt and it may be worth attempting to perform a check to correct any potential errors before attempting a restore.
To check, restart your computer and as previously instructed, continually press F8 during the boot process to access the 'Safe Mode' screen as before, but this time select the option 'Safe Mode with command prompt' and login in as Administrator.
- After you log on as Administrator, hopefully a blank window will open labeled as 'Command Prompt'.
- Within the 'Command prompt' window using the keyboard type the following character text "Chkdsk /F" and then press the keyboard enter key.
- In response to the windows message "Y/N" question that appears on screen, enter "Y" and press the the enter key.
- Now restart the computer and when Windows reboots it will commence a check disk operation and automatically attempt to fix any disk errors it may find. Let it run which could take some time depending on what it finds.
- When the process is completed Windows will restart automatically where you can then test to see if the problem is fixed.