They don't bind any keys, they do a HAL check. You must UPGRADE first.
Here is how to have your cake and eat it too.
First, create a restore point.
Restart if necessary into your current WIndows, and make sure you have a fully updated Windows environment. Once anything has been installed, restart. Assuming that is C: to to Windows\SoftwareDistribution\Download and delete everything in there.
Restart.
In the existing partition, download and install Minitools Partition Wizard and use it to shrink your current HDD to allow for a second partition (160GB etc enough to take the size of your existing OS installation). Press apply and let it restart and do its thing.
Now restart into the same original partition and use minitools again and then copy the existing windows partition across to the second partition - again with minitools (use partition copy/move). Press apply and let it restart and do it.
Upon restart and completion of minitools work, boot into the new second partition and fully update windows. Restart if anythning is installed before continuing. This should look and be exactly the same as the original.
Boot into the new second partition go the the registry edit (windows key /R) and type Regedit.
Navigate to Hkey_local_machine/Software/Microsoft/Windows/CurrrentVersion/WindowsUpdate and create In that top level a new Dword (32bit) (right click in blank area) called AllowOSUpdate. This needs to be exact - case sensitive and spelling. Then once created double click on it and change its value to 1 and apply.
Restart into the new partition created above and run windows update (on second partition - new one) of course. It should begin to download and install WIndows 10.
You will now have a dual boot with Win 8.1/7 (depending on what you have) AND 10 selectable in a GUI boot menu.