Boaxxe, PLEASE help!

Hi!

I belive I ahve gotten the Boaxxe virus. A few days ago my brother was using Internet explorer which I usually dont.
Something weird happend so after a few days I decided to install Avast! It found 4-5 different things and moved it to chest and also found some wierd program in the autostart which I unchecked for autostartup. Then I thought that was it
Then the window for system configuration kept poping up when I started the computer. So I ran the scna about 5 times (full system scan). Nothing was found so I thought I was good.

By the way I have an Asus eee 901 with XP.

The computer worked just fine and I even ran a defragmentation with no problems.
However when I stated it today Not one single program except for Avast! was started on startup, not even my network connections. Problem was that Avast! was disabled and I cant enable it again.
I cant log on to internet and cant use avast anymore AND I cant make changes in the system configuration because the virus has created a new administrator log in.

How do I get rid of it? I am scared of using a memorystick between this computer (not mine) and my Asus.
I have now downloaded Malwarebytes and Hijackthis but dont really dare to put them into my computer.
Because I might want to use the usb-stick back to this computer (my friends computer) to be able to give you a hijackthis log.
But that might affect my friends computer?

Tried starting in safe mode, and now I can actually log in to the administrator log in, but STILL can´t enable Avast!.

How should I proceed? Waht order? should I do it in safe mode?
I am not a super computer geek so detailed help is VERY appreciated!

Thanks for any help!

 

Would appreciate very much if someone could help me with this, as I have NO idea of how to proceed.

 

Hi!

Ok, so I couldnt stand waiting anymore and decided to try to put a USB-stick into my computer.
BUT IT DOESNT WORK!!!

Now I have NO idea how to proceed..
All network connection possibilities are disabled and my USB slots DO NOT work anymore..
Can a virus even do all this?