Solved as follows:
Reached Safe Mode by powering off two times then getting Diagnosing PC mode.
Then - Auto Repair
Then - Advance
Then - Troubleshooting
Then - Advanced
Then - Selected number...

I messed up my computer and need some real expert help to straighten this one out. Any assistance / suggestions would be appreciated. Details are below:

MY SYSTEM:
Dell E6400
Upgraded from...