Computers that run Windows 7 don't typically seem to have UEFI, and Linux novices often disconnect any separate HDD containing Windows prior to installing Linux for the first time, to make absolutely sure that they don't delete Windows by mistake.
Just a few built before 2012 had only traditional BIOS, while this built in 2011 backwards, probably when at least half of more of Windows 7 computers sere distributed, has BIOS only. 2012 brought many 'hybrids', for Windows 7 preparation & once that OS was released, all was UEFI.
I'd say that on just a dual boot of Windows 7 (even if on a UEFI machine, has to run in CSM anyway) & Linux, there's two choices. Grub & EasyBCD 2.3 from Windows.
Al has a point that we often push to newbies when there's two drives, in disconnecting the one with Windows to prevent loss of data or OS, and if Grub is desired for both OS, that's fine, once plugged in, can add it to grub by opening the Terminal & typing in the below command, or copy/paste, provide root password at prompt, and Enter, Windows 7 will be added to Grub.
The output will look something like this, but since am also running Windows 8.1 Pro, that shows instead of 7.
cat@cat-XPS-8700 ~ $ sudo update-grub
[sudo] password for cat:
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.19.0-32-generic
Found initrd image: /boot/initrd.img-3.19.0-32-generic
Found linux image: /boot/vmlinuz-3.13.0-24-generic
Found initrd image: /boot/initrd.img-3.13.0-24-generic
Found memtest86+ image: /boot/memtest86+.elf
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 8 (loader) on /dev/sda1
cat@cat-XPS-8700 ~ $
However, I use EasyBCD 2.3 as described above & also mentioned by bitesized1612, it's just easier for me & many others who has used the app over the years.