windows xp not able to update/restore iphone? i had the same problem for a long time.i read all the articles and no dice.So i ended up always having to use another computer(my brothers).but all that is over now.im sure it is an issue for all the computer savvy people who mess with there setting to speed up and tweak their PCs. so an indebted tutorial is not needed.

1. go to msconfig "startup" and "services" and enable every thing.in both tabs

2. go to administrative tools "services" click "status" tab and try to start every service that is not started.

this is a quick and easy thing to get your iphone updated or restored with your windows pc.im sure you don't need to enable all services but just for simplicity do them all and it will finally work.
i went threw so much headache for a long time.hope this saves some from the same thing.