Trust me, HijackThis is not a virus. There are online schools devoted solely to the use of this program. It's a powerful tool that aids in the detection of infections. Are you downloading it from the link Deerpark provided? Make sure you're not downloading the 2.0 beta version, which might still create false positives with McAfee. Version 1.99.1 is the version you want, and it shouldn't create any false positives, unless you have outdated software (looking back, you did say you have an old version of McAfee, which may be the problem). If you have to, disconnect from the internet and disable McAfee. Then download HijackThis with another computer, put it on a disk, and transfer it to your own computer. Then scan with it and post the log here.
Did you download the programs dl65 suggested and follow his instructions?
Also, would you mind asking your friend what he downloaded to fix this problem for you? It's becoming an increasingly popular problem, but there are still very few possible solutions.