I am running a home built Vista Ultimate Machine that has a builders version of Vista Ultimate. Can I do an upgrade to Windows 7 Ultimate and will it still be considered a builders version. If it is I will not be able to move the Windows 7 to another machine. Please let me know.

If it's not an OEM version, then you can use it on another system. Be aware that you can only use the OS on one system at a time.

Also, I recommend a 'clean' install.