It does not take much, as I am guessing that the trial version of the virus software was not turned on and a backup was not done onto a USB drive. At this point, you might try to get a copy of Windows 10 and do a fresh install using the EULA code that is on the bottom of the laptop or it should have come with the contents in the box. If that does not work, then you might also try taking it back to the store in which you purchased it and they could do a fresh install. You may lose some of the programs that originally came with the computer, but, the sacrifice of losing those vice the entire OS is small. Standby to pay out a bit of cash for this, because it does not come cheap, but you have learned a very valuable lesson. Create a restore USB, turn on the virus protection software. Good luck.