Following the instructions on this forum to update through Win2K is not hard. It is not risky, same risk as with WinXP. Most of the problems were with the T10 which is a bit different. Get your 1.71 firmware from here:
http://nyaochi.sakura.ne.jp/iriverupdate/
Now just read up on it, and you can do it. Use the right firmware (pure or non pure, get this right, UMS for your country). You shouldn't need a hybrid firmware anymore I expect, as iriver have allowed UMS for all now.