MS Office 2007 Service Packs, error 57e (1406)

I have installed MS Office 2007 on my Win7 Ultimate 64-bit machine. Upon installation, it gives me 1406 errors saying that it cannot write to certain registry items. I click "Ignore" and it goes on and installs anyway and seems to work OK. When I attempt to update it to any SP (1, 2 or 3), it eventually tells me that the update installation has failed. I have a dual boot computer with WinXP Pro...