Black screen+Mouse active+Windows wont start

After Windows start up all I can see is a black screen and an active mouse cursor.
I am able to get task manager to open and even to activate Chrome (from task manager).
Other things doesn't work (e.g. can't open folders).

I've checked the "shell" value in regedit (it's "explorer.exe") but I really don't know what else to do.
I'm working with Windows 7 Professional.


Any ideas?

Thanks!

Work through the steps for Troubleshooting Windows 7 Failure to Start
which try everything possible to start the OS, leading up to if necessary rescuiing your files to run Dell Windows 7 PC Restore or do the superior Clean Reinstall Windows 7

If this is the Dell in your specs then there is a built in Dell Hardware Diagnostics from F12 Menu to test your hardware first. If necessary to reinstall and not run Recovery, be sure to save the Dell Utilitiy partition to keep these bootable diagnostics.