Error 3002 when upgrading to ios5 in windows7

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Hey people, so when I try to upgrade / restore to the new iOS 5 beta I get error 3002. I have upgraded to the latest iTunes (the developer preview one designed for iOS 5 beta) and have tried option+restore and option+upgrade. Any ideas?
Itunes:10.5
Iphone software version:4.2
Operating system:windows7 ultimate
I don't access to mac!please slove my question for windows7!
Edit:i'm not devloper but i like to test ios5.please help melease:

 

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Any idea???
Please help me quickly!