I just updated my iPhone 3G to iOS 4.2.1 and I am trying to jailbreak it with Redsn0w 0.9.6b4 but it keeps getting stuck on the "Uploading ramdisk" phase...can someone please help? What should I do?

there has been a solution posted before. The fix was to go to task manager and set the affinity of the redsn0w.exe process to only one cpu (assuming you are on a dual core processor).

Depends. The CPU Affinity fix was for when the redsn0w application itself stopped responding and faulted -- I've experienced the failure listed below with 0.9.6 b1 and b2 and was unable to fix it by setting the CPU Affinity or running in compatibility mode for Windows XP / Vista.

It's definitely worth testing to see, but I tried for so long and was so unsuccessful that I ended up having to use limera1n and then de-hacktivate/re-activate legitimately.

Beyond that, this issue was already discussed on several other threads -- please search before posting, saves the users and moderators the frustration of answering the same question and ensures there are as few places discussing the same topic so anyone who finds one can be sure they're getting the latest info.

Thanks!