Hi everyone. I was given an old iPhone 3G, iOS 4.2.1 over the holidays, and have been trying to jailbreak it with redsn0w 9.10b3. Unfortunately redsn0w crashes as soon as I put the phone into DFU (by crashes I don't mean hangs, but the process just quits). I've tried disabling my antivirus. Any other suggestions?

Unfortunately, the newest version of redsn0w does not jailbreak all previous versions of iOS -- each version of redsn0w is specific to versions of iOS. If you want to jailbreak iOS 4.2.1, you will need to use redsn0w 0.9.6b4.

Beyond that, there were issues with older redsn0w revisions on machines with multiple core processors, where you had to go to the properties for redsn0w.exe in task manager, change the CPU affinity to only run on CPU 0, then run the jailbreak process. This may or may not apply to you.

Last but not least, if you're running on Windows Vista or 7, ensure you're running the program as Administrator and not in the context of a standard user.

Thank you very much for your precise answer, Mr. n4m3. All three facets of your prescription were indeed necessary, including setting the affinity (which I tried to avoid the first time around = curiosity/laziness). And successful!

So i'm working on an iphone 3g and was running into issues as well using the latest redsn0w. The steps you gave on this post worked to get it to run but it did not give me the option to upgrade the baseband to 06.15.00 which i am on 05.15.04, so I believe I need to upgrade the baseband in order to unlock. Any help?

TDenn

****UPDATE.... Figured it out following steps on iclarified.com. Just took forever to find beta 5 for redsn0w...