iphone software problem updating

[dave maden]

downloaded the latest iphone software - when preparing iphone for update - all content removed - but failed to re-load new soft ware - error 1604 - phone in recovery mode

tried a new usb port, new usb cable - - manged to update ipod on same computer/itunes account - so no problem with computer


Tried to update iphone from a laptop - remains in recovery mode - now giving error 20

Any suggestions?

Thanks

[AMD_K7]

do not update make a restore and try.