SOLVED monitor goes dark with user account dialog & start menu programs have vanished?

[BJ33813]

I dont know why, but the past few days I have A problem.
When I try to launch a program, the user account nag Do you want this program to take control etc pops up, I click OK, and the monitor screen goes completely black and I am forced to shut down the pc and restart it, Happens on every program where the infamous User Account sticks its nose in. Cannot run any process that the User acct settings work on, so therefore cannot shut off the User acct control either.

Tried a sys restore, nada. Went back to a saved image from early September, and it worked fine for one day, and now doing the same again. AV scans show no problems.
Dual boot SSD with win10 on C partition, and Win7 on D partition. Win10 working fine.
Thanks for any help.

 

[BJ33813]

Update: had to reset all my programs for the startup menu, and they are holding, so that problem is solved.
Still no luck with the monitor losing signal tho.

 

[BJ33813]

Since its all UAC related, decided to create new admin acct. Seems so far to work, as I was finally able to reset the UAC security level down one notch so will get fewer UAC nags, and so far, no black screen.