My job is computers repair.
If the computer has been infected with a virus/trojan, and it is not allowing internet access, and you have data/music/etc stuck on your computer that you need. The easiest way to do this is: -
1. You will need access to another computer
2. You remove the infected hard drive from your computer
3. Connect it to the other computer as a slave drive.
4. Boot the computer
Your now connected slave drive will not have any files that are active allowing the full removal of any infected files, you can also now save any files that you need. Now run the virus checker through your disk and any infected files found will be removed. once virus checker has finished you can now replace your ( now Virus free ) hard drive back into your own computer case, and assuming that no windows files were removed during you virus scan you should have a fully working computer.
Mike H
May 2009