I bought a Windows Ten Pro key and it doesn't work...

Change product key to the Windows 10 generic Pro product key:
VK7JG-NPHTM-C97JM-9MPGT-3V66T

Once the upgrade to Pro finishes, change product key again to your purchased Windows 10 Pro product key. You can't do an upgrade with an OEM product key.

Edwin said:

You said your machine booted into W10 Home, you're entering a Pro key, why don't you install W10 Pro?

The product key in the computer's UEFI is blocking the installation of Windows 10 Pro. The solution is to put the Windows 10 Pro product key in a PID.txt file, save it to the \sources folder of the Windows 10 installation USB flash drive and that will override the Windows 10 Home product key stored in UEFI.

Edwin said:

You said your machine booted into W10 Home, you're entering a Pro key, why don't you install W10 Pro?

How do I install pro? I created a boot disk using MS's media creation tool. I booted the laptop from that and was never asked what to install. How do I install pro?

CVRIV said:

How do I install pro? I created a boot disk using MS's media creation tool. I booted the laptop from that and was never asked what to install. How do I install pro?

See my post #11 above on how to upgrade your 10 Home to Pro.

And, ironically, my post #11 here for detailed instructions how to install 10 Pro:
Method of buying Home to Pro Upgrade that gets a Re-usable Key?

NavyLCDR said:

See my post #11 above

And, ironically, my post #11 here:
Method of buying Home to Pro Upgrade that gets a Re-usable Key?

Ok ill try that.

The generic key worked and I'm "Preparing for upgrade". If my key is fine.... do I have to do this every time I reinstall windows? Could I somehow remove the "injected" OEM key? Would that prevent this from happening?

Ok. what you told me to do with the generic key didnt work, but the PID.txt thing did. I want to delete the windows 10 product key from computers bios so I dont have to worry about this again. I want it to just ask me what to install.

I bought the key through bonanza from a seller, quick_deal. I basically googled windows 10 pro and found the deal through google shopping.

CVRIV said:

I want to delete the windows 10 product key from computers bios so I dont have to worry about this again.

Then you will have to either solder a new BIOS chip onto the existing motherboard, or replace the motherboard with a retail off the shelf one.

CVRIV said:

I bought the key through bonanza from a seller, quick_deal. I basically googled windows 10 pro and found the deal through google shopping.

You got what you paid for - a product key that violates MS licensing terms for you to use on your computer. When you pay $15 for a "license" for Windows that retails for $200 - you have to ask why?