Let us first try to do a system restore to fix the issue, for that you would need to follow these steps:

1: Power on your computer, start tapping the F8 key.

2: Once on the Advanced Boot Menu, select Repair My Computer.

3: You would come to a prompt to select Language options, let that be default.

4: On the next screen you would see System Recovery Options, Select System Restore & then a date prior to the issue.

5: The rest is self-explanatory, the system will reboot and you will be able to use the system again.

In case the system restore fails , we would need to copy your data using a linux distro or perform an upgrade using the Windows 7 disc. That way too your data would be safe. We will provide the necessary details once you go through this process. Please keep us informed.