I had to flash my phone when it got stuck with PR1.3 update.

First I tried with Win7, but it did not work. I was able to reflash with a different computer on WinXP. AFAIK, Win7 does not work, as it has stricter check on driver signatures and Nokia has not signed the driver in question. Win7 driver validation check can be relaxed, but the procedure is complicated, so better find an XP computer.