I have win 7 pro oem already changed to 10 on a HDD, I should have put it on my SSD but didn't want to destroy my existing OS on that drive in-case I lost important stuff. There isnt enough space on the 120Gb to play with and I had to shift around a lot of stuff just to get 10 on my HDD's (I need moar storage!)
I could do an image (i guess) but then it would be a HDD image not suited to SSD, I'm now happy to destroy the 7 install that resides on the SSD (which is a separate home premium 7 retail which will go to my HTPC).
What are my options now with the least likelihood of fubar?
I would first backup all files that you really don't need and download the drivers for your networkcard/cards.
If you don't have the storage capacity, I'd use cloud storages like google drive and dropbox (With win10 NSA will have your files anyway). Make an account here and there just to get the stuff off your computer. Then when you just have the bare necessity I would recommend using Windows Easy Transfer. Transfer all files and settings to an external drive, thumbdrive or even a dvd. If you don't have one a friend might. When you start Windows Easy Transfer it tells you how much storage you'll need.
After that do a fresh install of windows 7 or 10 (if 7 is "upgraded") on your SSD. You can download an ISO from microsoft
Windows 7: http://www.microsoft.com/en-us/software-recovery
Windows 10: https://www.microsoft.com/en-us/software-download/windows10
Maybe this isn't what you were searching for and I'm completely wrong in what you were after, in that case I blame the english the swedish schoolsystem taught me.
I basically just want to move the pro OS onto the SSD but am concerned by the fact it is an OEM installation and currently on a HDD, If I simply try to fresh install onto the SSD will it not complain that the key is already in use?
I have installation media for 7 pro oem
I have a suitably sized usb drive in a caddy knocking around somewhere so can offload some of my stored files onto that if needs be or onto my HTPC via lan.
If activate Windows 7 online fails you can just activate by telephone by
running (win+r) "slui.exe 5" for steps or "slui.exe 4" for direct choice
Or just choose from Control Panel\System and Security\System
Select your country, dialing your specific
number and follow instruction.
The automatic activation, most often, doesn't care about who's the supplier.
It works 100% half the times.