sounds like you've been hit with a Virus, the scammers load up fake downloads and websites with them.....google CA Antivirus(computer Associates) on another computer, then download the free 30 day trial, put it onto a CD or a Blank DVD and then shut down the computer you have trouble with......pop the DVD Drive open with a straightened out paper clip in the little unlocking hole on the drawer, put the DVD in, push it closed, hold down the escape key(esc) on the computer while pushing the power on button, select start in safe mode using the up and down arrows on the bottom right of your keyboard, once you have selected the "start windows in safe mode with command" by highlighting it, hit enter.....when the machine starts up, open up the "my computer" on the start menu, click on DVD Drive, right click the icon, scroll down to "explore folder" then double click on CA Antivirus, it will install and run, splatter the virus then mop the floor behind itself....
you can now pop the DVD drive open, take out the disk, shut down the computer, push the start button and you will be back to normal....
A restore to an earlier date will not work, as the Virus has already zombied that...