Make sure you wait until the computer would be fully loaded before trying this, and not try it right away like you would to say get into BIOS. This needs you to actually be where you would be when Windows Explorer loads.
1. Press "Shift" repeatedly until the "sticky keys" window shows up.
2. Now click the the link there that will lead to the "Ease of Access Center".
3. Next click "Cancel" on the the bottom right corner of the "Set Up Sticky Keys" window.
4. From here you want to click "Control Panel" on the upper left corner (it should be right beside the "Make Your Computer Easier to Use" title.
5. Locate the "Computer Settings" menu and then choose the "Recovery" icon (make sure that your view of this is by either large or small icons for easier access).
6. Now click and open "System Restore".
7. Here you want to click next on the bottom right corner (a few times) until the button "Finish" shows up and then click it. (Just follow everything prompt that the window says which will lead you to recovering your previous system, in a certain time.
8. The computer will now do the work it needs to and then reboot.
If that doesn't work, you can try the following...
You can also try doing the Ctrl+Alt+Delete and see if you can get "Task Manager" to show.
If the "Task Manager" windows shows, then choose "New Task" and then type in EXPLORER. If the desktop shows up then you need to go into "Start", "Programs", then "Accessories" and finally "Command Prompt". (Or you can do a search for CMD.)
Make sure you load the "Command Prompt" with Administrator access. Then when it loads type in....
It will do a file check.
To learn more about "SFC" visit this link at Microsoft... https/support.microsoft.com/en-us/kb/929833