I've searched extensively and can't find a solution for this; I can do it with a dual boot of two different XP installs, but Windows 7 and XP is eluding me.
It's easier if I just tell you the end result of what I want things to look like; then maybe someone will know how to accomplish it.
I have a laptop that currently has Windows XP (installed first) and Windows 7 (installed second) as a dual boot configuration.
What I want is to completely (temporarily) eliminate the boot menu. I don't want to just "limit it to 0 seconds" or anything like that -- I literally want to eliminate the boot menu. I want it so that when you boot the laptop, it boots Windows XP every time.
However, there should be "some method" to restore the boot menu - preferably by running a batch file in Windows XP. After you boot to XP, you can run this batch file, then reboot the computer, you'd get the boot menu and have the option of choosing Windows 7.
Once in Windows 7, you should be able to run a similar batch file to remove the boot menu again - so that when you restart the computer, it once again reverts to just booting to XP and doesn't display any menu, until you run the XP batch file again.
In XP I would have been able to do this with a batch file that rewrites boot.ini but since Windows 7 doesn't use boot.ini I don't know how to accomplish this from the Windows 7 side.
Also, let me clarify that I don't much care if the OS's can "see" each other -- I don't need to hide the drives -- I just don't want the boot menu to appear, basically making it "appear" that the system only has a single OS unless you are "in the know."