Hi everyone, I’m hoping someone here can help me 
I was surfing the internet yesterday afternoon when I picked up a JS:Prontexi. I’m aware that this is javascript embdedded into ads that infect you when the ad loads on the page? I was shocked when I got it, because I wasn’t even on any sites that looked dodgy (I was on Gillette’s website :P)
I was using AVG free antivirus, and it detected it and moved it to the vault. My firewall (ZoneAlarm) came up with a few things asking if I wanted to grant them internet access (including one that was AVC.exe if I remember rightly) so I thought maybe it was related to AVG. So I uninstalled that and downloaded avast! I did a thorough virus scan using avast as soon as I installed it, but it didn’t detect anything.
However, this morning my laptop has been running incredibly slowly and I figured that the trojan was probably still lurking there somewhere. And sure enough avast did detect the trojan about an hour ago and moved it to the chest…but my laptop still isn’t running quite right. 
Is there anything I can do that doesn’t involve rebooting the whole system (stupid me didn’t make a backup disc - kept slipping my mind - I’ve not had this laptop long), or will I have to do that?
Also, is there anything I can do in the future to prevent this happening again? Or since I have avast now should I be protected in future?
Thanks for your time