Black screen on start up

Black screen with curser in center. Without clicking the mouse, dragging the mouse draws a blue box. Acts like the left click button is stuck. Control/alt/delete-task manager has Skype program running and some times another program. If I end all tasks, computer begins operating normally. Tried system restore to an ealier date would not complete. That was probably from not disableing virus protection. Any suggestion of cause?

Did you make any changes before the weird behavior? I'd undo them or try System REstore from System Recovery Options.

I would also establish a Clean Boot from Troubleshooting Steps for Windows 7.

If those fail then work through the other steps, report back results.