I looked at Wikipedia, and there's no mention of a PC version at all.
http://en.wikipedia.org/wiki/.hack//fragmentI think your friend is missinformed.
You know... I noticed that a lot of .hack fans have friends who are either liers, or just pretty missinformed. (Anyone remember the guy who was 100% convinced that there was a .hack//G.U. Vol 4 and 5 in Japan, and that his friend coming back from Japan was getting it for him in a few days? lol)