Error 21 fix! (Can't restore iphone 4 ios 5.0.1 jailbroken)
Fix listed in post #4.
I have a verizon iphone 4 that was jailbroken. I was having some random reboots and wanted to restore the iphone using itunes. I backed up the iphone, tried to restore it, and got the error 21 message through itunes, "the phone "iphone" cannot be restored. An unknown error occurred". So I turn the phone off, hold the home button until itunes says it finds an iphone in recovery mode, and run into the same error every time. Any ideas on how to restore my iphone?