Where did you create the vanity address? Did you have 2-factor set up? You don't need to throw out your comp but I wouldn't use it to store or send bitcoins unless you know its safe as you could have some keylogger malware.
Im throwing it away :-( i already have new one paid for i was about to go pick up before i seen this
Well if you're going to get a new computer, make sure to have extensive security measures installed.