Virus

If you partition and format the HDD then it'll take care of the virus. Is this is primary or secondary (slave) drive? It sounds like a primary...

Partitioning the drive won't do anything. And formatting the drive should be a last resort.

There is a malware guide in my signature. Run through that.

If it's a slave drive then wiping it clean really isn't a big deal...which is why I asked if it was the primary drive or not. Formatting would be the fastest, most simple and most reliable if it were indeed a slave drive and didn't have an OS on it. And the reason I said to do a partition too is because its always good practice to remap the drive before a format. The fact that he is having issues opening critical system utilities and folders would also lead to believe there might be an issue with the file system and a partition would definitely take care of that.

its the main drive in his, i can how ever add it to mine, i have win 7 and he has vista though. mine is protected by trend micro but i didnt want to take any risk of it effecting mine.

If you can't get the software that is mentioned in the guide, to install and run in safe mode with networking, then use the AVG rescue disc that is linked in there. It will boot the computer off the disc, and scan the hard drive. You won't need to put your hard drive in danger of also being infected.