Windows 7: Dual boot option missing

I have Vista and Win 7 dual boot from 2 HDD's. I would get the black and white screen that let me choose which I wanted to boot. I had to reinstall Windows 7 and now that option is no longer their. I booted from the Windows 7 update DVD and when I got to the part of selecting the partion I chose the one that did have 7 on it and formatted it then installed it. Why am I no longer given the dual option and is thier anyway to get it back? I have checked and my files for Vista are all still there.

The black and white screen is called windows boot manager.
First, try to boot from the HDD where vista is installed. If vista boots up properly, the problem is in the boot loader sector. To recall the vista bootloader, you may use Vista boot Pro (VistaBootPRO - Dual Boot Windows 7 or Vista with Windows XP). But the best option I think is to install EasyBCD (EasyBCD Download - Softpedia) .

First install EasyBCD in windows 7, then add a vista entry using it.

You can also boot to the install DVD, go to the second window and hit Shift+F10 or continue to the repair section and command prompt and type the following then hit enter:

bootrec /rebuildbcd

This will scan for any OS not already in the boot menu and add it if you allow.

Thaks for the help. I was able to get my boot menu back using Saltgrass's suggestion.