So I’ve been getting a lot of questions about how to install the iOS 4.0, and whether it will work. Here are a few questions/answers that should help you out.

Can I install iOS 4.0 on Windows?
Not currently. As of right now, you need iTunes 9.2 beta which is only availble for Mac. It may not be released for the PC until June 21, 2010.

Do I need to be a registered developer?
Many people have mentioned and asked about needing a valid UDID in the Apple developer network. This isn’t required because the current iOS 4.0 IPSW file that is floating around is the Golden Master (GM) which means that is the release that will be publicly available to the masses. Thus, no UDID is required.

How do I install iOS 4.0?
You’ll use iTunes. Backup your phone as you always do. Download and install the iTunes 9.2 beta. Just google it, I am not providing links here. Once it’s installed, click Alt + Restore in iTunes and select the IPSW file that you downloaded – iPhone2,1_4.0_GM_8A293_Restore.ipsw – let the restore happen. That’s it, you now have iOS 4.0.

Have fun!