Vista

[MOHAMMED1997]

How To Upgrade From Vista Eterprise To Vista Ultimate

[jrk86]

I believe that would be a downgrade no?

[c4consulting]

This will only work if you uninstall sp1 first hope this helps
Before inserting your vista ultimate cd

Go to start>run and type regedit.exe
o to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

Change the key : ProductName from “Windows Vista ™ Enterprise” to “Windows Vista ™ Business”

Change the key: EditionID from “Enterprise” to “Business”

This tricks the install disc into allowing the upgrade feature as "business" edition can upgrade to ultimate

Now insert the vista ultimate CD select upgrade (you will notice this is no longer greyd out)