I have some trojans and I don't know how to kill them.
With Spartans.
Anyways, I use Avira anti-virus, and it's worked alright for me so far. Dunno how much of it was because of the anti-virus and how much was luck, though.
If he can't use the computer without the virus affecting it, then he can't install the antivirus program. Unless this is possible in windows safe mode.
If I were you then I'd instal AVG, yes there's a free version of it. Then I'd use Firefox or Google Chrome because those web browsers have the most security, then go look for security add-ons with the browser.
I'm using Firefox and I have several security add-ons. I also use AVG anti-virus.
Well you dont want to get a Anti Virus program, they dont remove trojans or malware. Maybe try Spybot or Ad-aware. They both come off Download.com for free. Might as well try it. Also, check and see if Windows firewall is on (if you use windows).
I was on AG when it happened, I was going through the games and it popped up.
Nothing seems to be the matter now.
Generally; Trojans are just used for key logging and for the person who put the Trojan there to be able to view any private information such as passwords, login names, etc. Normally, it is not actually apparent that the Trojan is there or in effect.
I use AVG running in the background. If I suspect I have a virus (mostly if I accidentally went somewhere suspicious) I bring up Malware Bytes to scan afterward. I have ad-aware running to help just in case. I also use Winpatrol. It alerts me of any new program changes (I use it mainly to help organize start up programs, but it has added security benefits as well). Getting them for your computer won't hurt at least.
Well if you try other stuff and you can't do anything to it, I'd recommend following your computers 'reload' procedure: Follow the manual instructions to find out how to do that. You should have a selection of about 10 autosaves to choose from. Pick the one with a timecode of a few days before you clicked something that caused the infection. It should wipe everything that happened since then, which sucks, but if it's what you need to do, do it.