Have a Hard Drive with Windows 10 on it but can't make it work in new computer

[Finn123]

I built a new PC and instead of buying an OS, I decided to put my old hard drive from my old computer (that has Windows 10) into the new one. I set the boot priority in BIOS to this new Hard Drive, but when I boot, I get these messages: 1: no virtual or physical discs detected 2: no hard discs detected. And then there is just a blinking underscore that goes on for at least 10mins (haven't tried to wait longer for something to happen). Please help!

 

[Colif]

Can you put hdd back in old PC? if so, I would do that and then follow these steps: Reactivating win 10 on new hardware - that will let you move windows to the new PC. that is step 1...

Step 2: It looks like you need to fresh install to get windows 10 to work on PC, so backup anything on that drive you don't want to lose.

Step 3. download the Windows 10 media creation tool and use it to make a win 10 installer on USB

Step 4: change boot order so USB is first, hdd second
boot from installer
follow this handy guide: http://www.tenforums.com/tutorials/1950-windows-10-clean-install.html
when you reach screen asking for licence, click "I don't have a key" and win 10 will keep instyalling, and once its finished, follow the link in step 1 again to reactivate win 10

If you couldn't put hdd into PC on step 1, then you might need your licence info from old install and call MS as there should be a contact method showing on settings/update & security/activation page