installing ubuntu and starting windows isn't in boot option

I didn't installing ubuntu alongside my windows7.

I have windows7 installed in my ssd and ubuntu in another.
Right before I install ubuntu, I unplugged all my other hdd. 1st because it the ubuntu installation somehow didn't detect the hdd I want to install onto and 2nd because in that way I would be I didn't choose the wrong hdd to install ubuntu onto.

After ubuntu install is completed and running, I plugged my windows7 hdd and other storage hdd back.

But somehow when I restart my pc, it didn't even ask which os to use it just directly goes into ubuntu. I used F12 to have the option to select device to boot up with and I can clearly see my windows7 ssh and of course by clicking it, windows7 boots up properly.

I went into my bios and check my boot priority and options. There are only two boot options and the first is my ubuntu hdd and second is my optic drive. When I try to change the boot option, those two are the only options I can choose from. I cannot choose from any other hdd.

Can someone give me a hand?
Not sure if this is the place to post my question but this happened after ubuntu installation.

Thanks in advance people.

If you are looking for grub loader, please enter the following command in ubuntu-

sudo update-grub

After executing the above commands, reboot and check if the grub loader appears.
I had faced similar issue where I did not get the option to install ubuntu alongside windows and Ubuntu was loaded automatically. After executing the above mentioned command, I got the grub loader where I could choose the OS to load.

Hope that helps.