Blocked Laptop

For a few weeks I have occasionally received bogus!? messages about a possible Infection; however, the machine continued to function according to established parameters. Each time I contacted Microsoft I was insured, beyond doubt, that I had suffered scams, as Microsoft NEVER sends out notices instructing the customer to call the number on the screen.
Sorry, I apparently posted before I wanted to. Two days ago I attempted to install a payed-up Ultimate package. The computer fought me at every turn. I never did finish the install. This morning I turned on the computer to continue the battle. I right away received three messages on screen advising me that Windows had detected a virus and had blocked my machine until I called the number on screen. Another message said that Javascripts were not accepted, so again, lockdown. The machine was frozen and cannot navigate at all.