I know this is quite late but if anyone else has got similar problems, then you might find this useful.
I had the same problem as described on the title of this thread. On start up, a message from microsoft kept popping up asking me to allow it to make changes to the computer. The only way I could do anything without clicking yes was to constantly click no and and escape and somehow it let me work on the computer with the message still flashing. I went to the registry into the following location: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
In that I found labsdhtv.exe and I tried to delete it but it didn't allow me as the program was already open. I rebooted the systed in safe mode and I entered the location on the C drive in users/appdata/local (or similar to that) deleted the labsdhtv and deleted all the additional files created on the day of the virus attack. Once I rebooted the system the virus disappeared and my computer is now back to normal.
I found this forum extremely helpful so thank you for all the information. I hope my post helps anyone that's got similar problems.