why wont webroot remove this virus

So, I've had this "virus" for a couple weeks now. Whenever I try to play a game that's demanding of cpu and RAM, like, let's say, Apex Legends, my computer will completely freeze and the game will crash on startup. My computer freezes for about 10 to 15 minutes at a time. Webroot tells me I have a virus, but won't tell me WHAT it is, how to find it, or if it removed it or not. When I do a full scan, it's apparently gone, but when I restart my PC, the virus comes back. Is there any reason so as to why Webroot is incapable of permanently getting rid of this virus.