iPhone OS 4.0 has been available for a few days and I'm sure there are many of you who still have questions about the new version of iPhone OS so in what follows I will try to explain the most frequent questions regarding this subject.
1. Where can I get iPhone OS 4.0 beta? Can I use it?
iPhone OS 4.0 beta is available on the internet, Google will help you find it, but for now you CANNOT use it because this beta version of iPhone OS is only available for developers, and in order to use it you must have the phone's UDID serial in a developer's account . However, iH8sn0w a announced that it will release a version of sn0wbreeze that will allow us to restore to iPhone OS 4.0 beta, so be patient and don't bother installing it.
2. Is this version of iPhone OS 4.0 the final one?
No, this version of iPhone OS 4.0 it is a beta, available only to developers and ONLY works for a certain period of time, after which Apple will block it and release a new, much improved beta version.
3. If I updated to iPhone OS 4.0, will I be able to use the phone?
iPhone OS 4.0 beta comes with baseband 05.13.03, baseband version that CANNOT be decoded and will NOT be decoded until the summer, so if you update to iPhone OS 4.0 and do NOT have a neverlocked phone, then you will not be able to use the phone's telephony function until the summer.
4. I updated to iPhone OS 4.0 from iTunes but the Emergency Mode screen appears (iTunes icon and a cable), what do I do now?
I detailed the terms of use in point one iPhone OS 4.0 beta, so you are NOT logged into a developer's account, so you CANNOT use this version of iPhone OS 4.0.
5. I updated to iPhone OS 4.0 from iTunes, how do I jailbreak/decode?
At the moment MuscleNerd a PROVEN ca iPhone OS 4.0 it can be jailbroken but at the moment there is no software available to do this, there is NOTHING for decoding and there won't be until summer.
6. I have an iPhone 3G with bootloader 5.08 and I updated to iPhone OS 4.0 beta, can I downgrade the baseband?
No, for now there is no program that can do this.
7. I updated to iPhone OS 4.0 beta, how can I go back to firmware 3.1.2/3.1.3?
If you have an iPhone 3G then it's very simple, follow this tutorial. If you have one iPhone 3GS then things get a little complicated because you have to have SHSH saved in Cydia to restore to firmware 3.1.2, but if you have you can use this tutorial to revert to the old firmware version. If you don't need firmware 3.1.2, then you can quietly restore to firmware 3.1.3 from iTunes.
8. I tried to update to iPhone OS 4.0 beta from Windows but I get an error, why?
It seems that at the moment ONLY Mac users can update to iPhone OS 4.0 beta, and Windows users have to wait for Apple to solve this problem.
