I have been using my iphone 3 for a few years now and I found it is very slow after iOS many upgrades (now it is running 4.2.1. I remeber the original version was 2.1 or something, not sure what the exact number was though). Do we have an easy way to reset everything (including the OS) back to the factory state? As it has been for so long, i cannot even find the very first backup -- Do I still have a way to bring this iphone back to the factory state at all? or do we have a way to know what the original version it was? - basically I look for something like windows home edition in PC ... one key sequence can bring the PC back to the factory state (if the hidden partition is not deleted or messed up). But not sure whether there is such a thing in iphone world.
Thanks.
Thanks.