New
#11
Post 2 pictures of Disk Management.
1 from Windows 7 and 1 from Windows 10, then we`ll tell you what needs to be done.
The reason you can not boot from the new drive with the old unplugged is because your system partition is on the old drive.
You need to write the system files to the new drive, then when the new drive boots on its own, you can do whatever you want to the old, after marking it inactive.
Bootmgr - Move to C:\ with EasyBCD
The reason you are getting the wrong version message is either you are not using the same version of windows, different bit version, or different service pack version.
And you do not have to create a 100 MB System reserved partition, just write the System files to C.
This why you need to UNPLUG any other drives before installing any version of windows, or any other OS for that matter.
But 1st we need to see the shot of DM.
And for future purposes, you should not be saving any data, pictures, videos, on your C partition or even the same drive, if you can avoid it.