|In order to accomplish what you want you will need to have a third party boot manager. I have used BootIt NG for many years and have had to have xp installed multiple times ..all with their own activation licenses. of course :).|
A free program called GAG has come a long way and is very similar to Boot IT NG.
Because of the limitations on how many primary partitions are allowed the best bet is to allow the new boot manager to create the partitions for you.
Once the partitions are created all operating systems will boot up as "C" drive. I must also state that it would be best to install to different drives, but it can be done as partitions and drives are seen as the same through any operating system and you should not have any problems with it so long as you do not try to share programs. Sharing a program is a no, no, no in this type of system.
BootiT NG will allow 200 + primary partitions if your system can handle that.
GAG only supports 9.
You will need to install the boot manager first before any partitions are created. Once the boot manager is installed then boot to it and follow the prompt for creating partitions and installing each operating system as IT IS THE ONLY OPERATING SYSTEM INSTALLED. This means that all drivers and all hardware/software installations must be installed separately as well. You can not over ride this so don't mess around or you can screw up the whole process
One thing I found to be easiest is to actually name the partitons so that they are seen in that aspect instead of Windows XP or windows 7.
In my situation I did a lot of film editing and needed a stripped down version as the background applications kept screwing up my work. I named it Films, then another operation was Games and I had one named for my wife as I did not like the Switch Users program in XP.
I never had any trouble setting up data partitions and using them so long as they were shared through all operating systems....but again be warned about sharing application files and back ups as these can cause issues later on...
For cleaning utillities in this set up, stay away from Norton or McAfee as these see the system as one unit. Ccleaner and other applications...be sure to check the for this installation only box as well. Install them on every operating system and set the preferences to only scan that system.
XP has some issues identifying other drives between H and T for some reason. I moved my optics drives to the "Y and Z " letter designations, This allowed XP to read any USB drives and see them much easier. In the Lower letter designations.
I ran this for a number of years as I couldn't afford multiple computers during that time. I never had any issues with it till DRM showed up and I lost two whole drives of music files over a bad DRM installation in which it is my past time in still trying to recover the lost files. What I did discover is that in dealing with the music files the files that I had installed in their own folders were not harmed. Only those single files songs got made unreadable and thus unrecoverable.
Hope that helps you!