HEEEELP PLEASE! Installed two antivirus software p.c frozen

[Kordakh]

I've recently discovered that the a virus (Infopass.Gamestealer to be specific) has somehow made its way onto my flash drive. It is most likely from a computer I share with the other four hundred or so at my school, but I'm unsure how to remove the virus as Norton (Yes, I realize that it's terrible in terms of virus detection, but it's all I have.) isn't detecting it when I scan the drive. As a result of this virus being on my frequently used flash drive, I've managed to let it drop some malware (Hacktool.Rootkit) onto my personal computer. Norton only ever detects this one when I turn my PC on and never catches it during any of my scans of the computer. Are their any suggestions as to how I can deal with each of them individually, or even both at once? Thank you all for your help! daily motivation daily motivation daily motivation daily motivation daily motivation daily motivation daily motivation