It is what is called the "Black Screen of Death (BlSod)/(KSOD)" if you are using Vista or the later Windows 7. There are many causes for the BiSod/KSOD... some may say it is due to Micro**** updates and patches or as what Micro**** claims that is is due to malware infection, most likely something from the
Daonol family of Trojans.
Google for it or I'll share you this site to give you some insights of the BiSod/KSOD.
here's one of many you could read:
http://www.pcworld.com/businesscenter/article/183502/three_tips_to_avoid_the_windows_black_screen_of_death.htmlFor a fix you may follow these steps:
After the black screen with cursor
appears, press the shift key several times (5 to 10 times). A window
should appear that reads “Go to the Ease of Access Center to disable
the keyboard shortcut.” Click on that item, then follow these
instructions:
- In the explorer window that appears, clear the address entry and type MSCONFIG then press enter. Run MSCONFIG.
- Uncheck the two items in selective startup and press apply, then restart the computer.
- The computer should start normally. Now click the Start button and
type MSCONFIG again, then press enter. Uncheck Windows Event Log and
Windows Event Collector, then restart the system.
This may or may not work on your state but your last resort is to extract your hard drive and back-up to another unit before re-installing your OS.
Hope this helps. Don't forget to rate.