Windows 10 install very slow on Mid 2012 MacBook Pro I made a Win10 USB installer using the media creation tool on my PC and I have a SSD in a drive caddy which replaced my DVD drive. 

I want to clean install Win10 to this SSD but the Win10 installer takes hours - no joke - to boot up and then it takes forever to start the setup.

I already installed it before but when booting from the disk after install it just ends in a boot loop. The USB drive should be working fine I don't think it's the problem. And the SSD in the caddy also works fine. 

Any idea why this is happening and how I can install Win10?
It had something to do with the problem I solved here:   HGST 1tb in mid 2012 mbpro not working in sata bay but drive seems fine.  After I solved that issue, the Windows install worked normally again