Best way to go from Win7 Premium to 7 Professional (Full edition)

If you Delete Win7 Pro off the old computer, you can use it's Product Key to Anytime Upgrade your new Home premium to Pro.

During activation it may take a robocall to MS to exchange a series of numbers which change the hardware signature tied to that key in MS servers.

Otherwise use Home Premium to see if it has anything missing that you need - if so, buy the less expensive Anytime Upgrade key.

Anytime Upgrade is explained in the blue link which Bill2 posted at the beginning of the thread.

I had a PC running Vista 32. I bought the full Professional Edition on Disc for the 64bit 3 months ago to speed up my current PC.

Now, 3 months on, I have purchased a new PC from DELL, newer chipset, mucho more RAM.. All things that come with a decent PC. It comes default 7 Premium. All I want is to get the Premium up to Professional.

I have no care as to what happens to my current PC (which will be unused as soon as my new one arrives, maybe tomorrow).

...

And yeh Greg the thing I am trying to do is not payout more for the OS. I am sure the Professional full edition came with the option to use on other devices, (once removed from previous obviously), hence why I bought that one over the cheaper OEM disc.

In that case, I'd remove the Professional Product Key from the old install, insert it in Anytime Upgrade on the new one to unlock Pro features in a few minutes time.

To uninstall the Pro Product key, open an Elevated Command Prompt, type slmgr -upk, hit Enter. This will make the old Win7 become non-geniune until you run slmgr -rearm to reset the 30 day activation timeout if you decide later to start up the machine. Would you like to revert to the native OS on that machine instead?

This clears the way for using the Pro Product key to Anytime Upgrade the new machine. Type Anytime in Start Search box to start the process, insert key when prompted. After upgrade it may require activation robocall to change hardware signature in MS computers, which would cause the old install to deactivate upon connecting to the internet if you don't remove it's Product Key first. Hence when asked the key question "How many computers is this copy of Win7 installed upon" the only acceptable answer is one.

Commands same as here: SLMgr Commands and Options with Windows Vista Product Key Activation » My Digital Life

Thought I would report back after a month or so after your tip...

And it worked brilliantly. New PC runs my old key, and I am currently on my old PC due to extensive rendering times, leaving the new one to it.. and this just says it isn't a genuine copy. Which is fine, hasn't enabled the PC to completely collapse in on itself which is good.

Thank you for the helpful tip, albeit belated.

Try these troubleshooting steps for the new machine's performance problems.

Its ok, I am just rendering an animation in 3DS Max + Vray and its just hi res, and taking ages, thats all :)