If you press ctrl+alt+del at the same time does it allow you to choose an option called Task Manager?
Click on the Processes tab and look for a process called explorer.exe. When you find it, click on it and then click on End Process in the bottom right of the Task Manager box. Your desktop, including icons, start menu, task bar, etc. will disappear. After they have disappeared, click on File -> New Task (Run. . . ). When the box comes up type in explorer.exe and press enter.