Windows 10: Reusing Windows 10 USB and key code

I bought Windows 10 at best buy, and upgraded my Dell Windows 7computer at home. I am still having problems with boot up errors. Dell OEM stuff I now want to install SSD hard drive and use Windows 10 that I bought at Best Buy but I usedproduct key code already on upgrading my Windows 7. How can I reuse product key code again on new SSD hard drive? I have old product key code from my Dell computer. Can I change product key code? Can I change product key code and put Windows 7 product key code on my old hard drive that now has Windows 10 and reinstall Windows 10 on new SSD drive and be able to use product key code?

Thanks for your help

:)

 

Windows 10 USB boot

Hi there, am not a windows 10 expert. I have a pc in the bedroom on windows 10, I messed up the bootloader trying to fix the xp on that system.

System wont boot, trying to repair via win 10 usb installer.

Downloaded the media creation tool to install windows 10 installer on usb stick. Not compatible with a host of usb sticks I have. Tried the usb sticks that others use, but I think they use rufus; as the media creation tool by win 10 does not detect the usb stick.

So quick question, the win10 machine i am trying to repair the bootloader is a win7 upgraded to win10.
If i were to use the usb win10 installer to "repair installation" does the version of the iso downloaded via the media creation tool matter?

There is three options:
Windows 10
Windows 10 Home
Windows 10 N

Also is there a step by step instead of using rufus as I want to try an alternative method of creating a usb win 10 installer. Preferably with more compatibility.

System is a asus sabertooth 990 (r2?) with AMD phenom X 6.

Also is there any other software I can load onto the usb that can repair the bootloader easily?
That would be the ideal alternative. Thanks

 

windows 7 key reuse

I'm asking the second thing, if I can reuse my windows 7 key on another machine without any problems. (sorry, I see I forgot to mention it in the original post ^^)

 

windows 7 key reuse

I'm thinking it's the 7 key he's talking about.
I was under the impression that MSDN keys were good for 5 activations (being retail keys that is, unless it explicitly says it's OEM) but I'm seeing that it's apparently good for 10 activations. After that, you just have to call microsoft and answer a few questions (i.e, is that key currently installed on another machine) and they'll give you the activation code. I've actually done that at least 10 times with the same windows xp key.

Personally, I have a win7 key from MSDNAA, and I'm on my 5th activation on the same machine right now, haven't had to call yet.

Not sure if it OEM keys are different, but I don't see microsoft saying no even if you have to call them.

Of course, make sure you say the key isn't being used at the moment.

10 activations sources:
http://help.wugnet.com/vista/MSDN-Vista-Activation-limit-ftopict23335.html
http://www.eggheadcafe.com/software/aspnet/29531954/deactivate-a-product-key.aspx