CAUTION - Do not upgrade Windows Family Pac

[M20GDriver]

Microsoft will only upgrade 1 of the 3 machines with valid Windows7 product code for the 3 machine family pack. Worse, the product code is them invalidated for the other 2 machines that are still on Windows 7. I learned this the hard way when I tried to upgrade a second machine on the family pac. I had to revert the first machine back to 7 to get support for all three. It was after 30 days, so I had to call them and do a complete reinstall of 7.

 

[Lutfij]

Hmmm that's quite interesting to learn seems there is more out there:
Windows 7 Family Pack Upgrade to Windows 10 Activation Error 0xC004C003
Trouble upgrading from Winodw 7 Family Pack to Windows 10?[/ur]http://arstechnica.com/civis/viewtopic.php?f=17&t=1292083