windows 8 & 7 on separate HDDs

[Pedram Yousefi]

hello everybody
I had windows 7 on my old hard drive then I bought a new one so I decided to install a win 8 on it .
now I have them on separate disk and if I want to use one I should select that Hdd on setup boot menu .
but there is a problem when I use windows 8 and decided to use win-7 It always perform checkdisk on startup , if I cancel that the drives that i used in win8 will no longer be functional.
what should I do? is it something wrong?
p.s : the drive letter of my win 8 is C in windows 8 itself but it's F in win 7

 

[dodger46]

Need to use Command Prompt to set up Startup to dual boot.
Open Charms Menu, restart your machine whilst holding down the Shift key.
Choose Troubleshoot, Advanced Options, then Command Prompt. You'll need to sign in using your Administrator P/W
At the Command Prompt, type
bootrec.exe /scanOS (Note space before /)

Should find Win 7

Type bootrec.exe /rebuildbcd

You will then be given a choice of OSs to add to boot. Choose what you want and type exit to reboot and you should then be presented with a choice of 7 or 8 to boot from.