BleepingComputer.com: Dad and spyware hunter

Hi. I am a dad whose son has repeat troubles with computer virus infections and hijacked browsers.
I've come here for help and advice. We've reformatted his hard drive a number of times
and reinstalled all software, only to get reinfected.

He insists it has nothing to do with his
browsing habits
gaming (free download games and web play)
facebook use and links accessed via friends' posts

He claims its probably a virus that was there before and keeps coming back in spite of reformats and reinstalls.
Also claims that companies that distribute games for web-play are legit and would not expose computers to viruses.

He's using an HP Core2 Duo PC with WIN-XP.
We've run programs like Malwarebites and AVGAntivirus.
Lately, web browsers seem to be hijacked and take user to ad-related sites.

Also, tried to run in Safe Mode and install HijackThis, but we got a message saying the Administrator has configured things so that it won't allow that program to be installed. I'm the administrator and never recall doing so.

This is just in the way of introduction, and I DO understand that I should post log files elsewhere.
I've Googled for help with the symptoms, but have to do it from another computer, or it takes me to ad-related sites.

Thanks for having this website. I've often found helpful tips in the past by Googling for help on issues,
and frequently find useful stuff here.

I will post my log file elsewhere.

Hello and to Bleeping Computer.

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