Many writers say: Microsoft has not changed there minds over the provision on CLEAN Install with UPGRADE Disk.
"Upgrade" from Vista 32 bit to 7 64 bit?
My reason to SAY: BUY the UPGRADE DISC.
Seems I'm the only STUPID person to buy a UPGRADE version of VISTA.
cheap or smart to save the $100.00 your decision, after you read the Vista Manual..
PS: you can cancell the FULL RETAIL and order a UPGRADE any time prior to the DISc actually being SHIPPED.