cannot update iPhone to newest OS

[SkepticDave]

How have others updated their 1.1.4 2g iPhone to the nevest OS? I downloaded winpwn_2.0.0.3 and created an ipsw file. In iTunes I held down shift and attempted to restore with that file. Kept getting error 1604 which is a USB communication error, and CRAP, because the iPhone is properly recognized and I haven't changed anything. But I did try moving wires to no avail. Fortunately Ziphone changed the mode back to operation which took a lot of trial and error, since it was in DFU. Because I got the 1604 and because it didn't look like anything was actually updated on the iPhone, I think it's OK like it is, and it works OK. But I would like to update to the current OS. Apple just released a new iTunes and a new OS again, so winpwn may be out of sync with that. Should I just wait until someone has something better for windows XP? Thanks