Jailbroken iPhone 3g 4.2.1 won't restore... HELP!!!

[Japagaijin]

I need help!! I have an iPhone 3G 8GB running 4.2.1 jailbroken with redsn0w, that won't restore. It keeps going to white screen, and then I get iTunes error 21. I have tried using tiny umbrella, and ireb, as well as just going straight into DFU, but nothing works... I have tried restoring to 4.2.1, as well as 4.1, and all that happens is when it reboots going into preparing to restore iPhone, when the apple logo should be coming up, all I get is white. Yesterday, my computer froze in the middle of a restore, it was almost halfway through on the itunes bar, then nothing, and I need my phone for at least another month... Anybody have any ideas??? I am running Win 7 Ultimate 64 bit on a emachines laptop w/1gb ram

 

[iGaz]

Try a different USB cable/port or both. It may also be worth trying a different computer...