multiple problems

[mdubs28]

Hi,

So I recently came home from college to find one of the family's laptop completely screwed up. Apparently they did not have protection as far as malware went.

I've been trying my best to fix the problems, but am coming up against a brick wall.

First let me outline the problems:
-A new administrator user account is created no matter how often i delete it
- Webpages will often not load in firefox or IE
- Google is hijacked, whenever I click on a search result it goes to a random site
- Lots of random popups


Now, let me go over what I have done:
-I have tried to dl and install HJT, which will not work
-I have tried to install Spybot S&D, it will not install
-I have tried to install MBAM, setup will not run
-I have installed and ran an AVG scan, however it encounters an error partway through and fails to correct any of the problems
-I have run xcleaner, but it does not seem to have helped though it identified some issues.

What I have found:
-The computer has the winscenter/spyware guard 2008 problem
-xcleaner found vundo, iteka, webbuying and winpop (but it is unclear if they were removed successfully)

Thats where I am at now. Any help would be much appreciated.

Thanks very much.