I can't access my desktop

Hi Newcomer and Welcome to the Tom's hardware forum.
Go to Task Manager!
select the processes tab and end the process with the image name 'explorer.exe' everything apart from the task manager will dissapear, just click on file>new task and run 'explorer.exe', this will start a new session. hopefully this is of some help.

+1 saran008
i've had to do this on peoples PCs before