The Boot Manager is installed in the first few sectors of the HDD (or SSD or SSHD). Whatever was done on this "other computer" has wiped out the Boot Manager.
I suggest that, while installing Windows (i.e. booting from Windows installation media), when you get to the scene where you select the partition to install to, make sure that you delete *all* existing partitions. When done, you should see only a single entry for unused space on the HDD. Select to have Windows installed to this unused space. This should restore the Boot Manager.
Let me know if this fixes the problem. There is a second possibility, but I won't go into it until we exhaust this one...
This message was posted on behalf of Intel Corporation
Great to know that your system is now working as it should.
If there is anything else you need, do not hesitate to contact us back.