thats the problem. if it doesnt load, then your computer wont load up the desktop. I suggest trying to get into the task manager, hit file, run, and type in explorer.exe
That should start it. If it doesnt, let me know and I will help you in getting a system restore/recovery going. Id attempt to repair the windows files before wiping it.
There may be different problems that cause the issue you are facing.
May be a video graphics driver update affected this(Generally happens with Windows 8). If this is the case, a system restore will do (given at the last of this post).
System crash due to some reasons.
Any other reasons (multiple reasons).
Try to press the windows button with 'R' key, if it opens run command, good for you else, try pressing Ctrl+Alt+Delete and in the task manager, go to new task and type in "explorer.exe", if that doesn't work, try again and this time type in "C:"
Just follow these steps :-
Start->All Programs->Accessories->System Tools->System Restore->Select a Date/Time->Confirm->Just wait and let the system reboot automatically
If still nothing works, you may format your windows drive and before that make sure you have got the backup of important files/folders, if any, on that particular drive.
this is the huge problem dude,
You can try as said by the KM 499,
And that's not working.
Try to run your PC on safe mode, and uninstall the last installed (that you installed on your PC atlast)
If safe mode is yet not working then I don't think there will be other way,
because wehenever it happens with me I Solve it by this way,
And when I go to Computer Shop: They Told me this all because of some viruses and having low ram.
So one of reason may affect your PC: Ram/Space. (It should feet the recommended requirements.)
If this won't work then Informed me, I will give some more advice/