I will admit, its been ages... so I could be remembering wrong... BUT, I could swear I had seen and/or used a tool that someone had made that allowed you to change the installed edition of Vista (sans reinstall)... Now I don't remember the FULL details, IE if this was something that could was done with the system booted or if it had to be done from a live boot CD (like hirens) or it was a script not a program ect ect... I jumped from Vista to 7 as SOON as it launched, I try not to recall Vista days, but I have a laptop for someone, they have a Vista Ultimate COA... so... bleh.. And its an HP... EDIT: for reference I am dead tired, and my 15min of google actually didn't result in anything useful for me...
Your posts seems confusing do they have vista installed at the moment or windows 7 if it is vista and machine came pre-installed and has slic 2.0 then you just need to do upgrade and enter vista ultimate oem:slp key.
Don't know how it is confusing BUT I thought that since I didn't mention the OS the laptop I had was running I left that in the "I want to upgrade it to Vista Ultimate so it must be a lower edition" line of thought... "I have a laptop for someone, they have a Vista Ultimate COA... so... bleh.." for reference the laptop has Vista Home Premium installed by default. The COA is from a Vista Ultimate Upgrade box he lost the media for, and the "Windows Anytime Upgrade" tool isn't available anymore, and I was trying to avoid torrents for the media... because, lazy...
Anytime Upgrade should be still available from the System screen (that lists Edition etc.). If the current Home Premium is OEM:SLP-activated, entering the Vista Ultimate OEM:SLP key will do the Upgrade to Ultimate. And due to the SLIC 2.0 in BIOS and the certificate still being in place, the Ultimate should be activated still. The COA key might or might not work for the Edition Upgrade, but, why wasting it?