running windows 10 64 bit.
i don't really know how but yesterday I some how got a virus on my PC that slows it down a lot and lock my fps in games to 30 and 40 (had before more that 60). desktop is stucky and my computer works very slow and stuck.
tried to restore system back in time from 5 in February, didn't work. ran a full scan in windows defender and it happened to use 97% of my CPU while scanning. tried to do an offline scan but in the middle of the scan it just stopped, windows defender closed and had a blue screen for 10 seconds and than it restarted. didn't help. tried to do a prereboot scan in avast an didn't find any threats. something strange is that only when I open task manager, the virus suddenly stop working and everything works fine but when I close task manager it quickly starts working again and my whole computer is getting slow and stuck. please is there any free antivirus program that can help me? or the last option is just to format my computer?
please I need help! any scan that I did with windows defender or avast didn't find anything. please help me!