I had to change a dual boot hard drive, put it in another laptop. Linux partition has no option to boot.

Windows 10, upgraded Windows 8, is the only boot option. It boots to it right away, does not show option to boot into Linux Mint. BIOS shows the hard drive, Computer is Acer Aspire 3, USB boot option does not recognize in BIOS, every time I tried it got 1 step into process and stopped. With different boot sticks, there is no CD/DVD in the machine. Have some data on Linux partition I'd like to backup. Help would be greatly appreciated. Steve Gere