Studio XPS 9100 desktop computer won't boot up properly

The symptom is that the machine will lock up and not respond (no errors come up) forcing a hard shutdown of the computer. Upon reboot, it never gets past the black screen with windows logo. The machine immediately goes into sleep mode, never giving the option to press control alt del to login.

Monitors have been switched out to confirm they are not bad. This seems to be a video issue (video card (nVIDIA GeForce GTS450)

Machine is able to startup in safe mode just fine. It will let you log in and both screens have a display on them. After multiple shut downs/ restarts, it will finally let you login as normal and work on it fine for the rest of the day. Problem returns the next morning when you turn it on again. 

• Ran diagnostics via (F12 option) and the following all passed: 

              System Board, System Management, VESA SVA Video

• Ran diagnostic for "System shuts down or reboots unexpectedly"- passed- this tested the CPU Fan and SYS Fan
• Ran diagnostic for "System locks up"- passed- this tested the above, & L1 -L3 Cache, and Hard drive

Uninstalled and re-installed the driver from the Dell support site: