Question : Win7 Ultimate upgrade in stages using OEM DVD

I am waiting to receive a Windows 7 Ultimate upgrade DVD that I purchased.  My XP installation is causing problems, and I would like to install Win7 now, without waiting for the new DVD.

I have a Dell OEM upgrade Home Premium DVD 64 bit.

1) Can I remove the EI.CFG file from the ISO image, and use this DVD to install Windows 7 Ultimate 64 bit from the modified image on a Dell notebook?

2) If I skip entering the product key, (since I don't have it yet), can I function normally including windows update during the 30 day activation grace period?

3) Will the Ultimate Upgrade product key work with this installation?

4) Are there any differences in product keys for different country versions of the OS?  i.e. if I install from a US DVD and then use a European product key, could this fail to activate?

Answer : Win7 Ultimate upgrade in stages using OEM DVD

1. deleting ei.cfg will give the the option to choose which version of win7 you want to install, so yes you can remove it

2. yes

3. it should do, if it doesn't a workaround (although a pain in the arse) is to clean install 7, then install it again immediately after, so in effect you are upgrading to win 7 from win 7

4. no - i got a win 7 product key from ebay from vietman and it worked on a UK installation