There are several layers where you can act.
Beware, however, that all these options can make your operating systems unbootable, if done improperly. You are responsible of what you do, please be cautious.
Bios-level boot menu
Modern BIOSes have an option for a "boot menu". Look at the BIOS settings. It can even choose other boot options, like CD, USB or network boot. But it needs to press a key (often ESC, F10 or F12).
- Pros: will work if you add or remove disks
- Cons: no personalized labels, usually just brand name of disks
MBR-level boot menu
MBR is Master Boot Record, the first sectors of the hard disk the BIOS boot on.
You can install there an OS selector. It will occupy the first few sectors of the hard disk.
- Pros: depend of particular program you choose. Independent of any OS installed, so you can install and remove OSes at will (even all of them), the menu will always work.
- Cons: depend of particular program you choose.
There are various programs to choose. For years I've used extipl. It is minimalist (text-mode menu, no labels just partition numbers) but always worked for me whatever the changes on my disks.
It may not be obvious when you read a description of a bootloader if it is MBR-level or partition-level.
Partition-level boot menu
If you don't install a specific MBR, the default MBR installed by Windows will just give control to the first operating system found. You an customize there.
Windows XP and beyond are customizable using
boot.ini. You can configure for a menu with personalized labels.
See this example from Dual booting XP on 2 hard drives - TechSpot Forums. Follow that link for explanation about risks.
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="XP on primary drive" /fastdetect
multi(0)disk(0)rdisk(1)partition(1)\WINDOWS="XP on backup drive" /fastdetect
C:\CMDCONS\BOOTSECT.DAT="Microsoft Windows Recovery Console" /cmdcons
There are probably some user-friendly tools to this more easily and prevent some dangers of manual editing.
- Pros: friendly (though text+keyboard-based), configurable timeout.
- Cons: attached to the OS, so if the OS is reinstalled or removed, the menu is lost.