Dual Boot system

[Mao]

I am now running a dual boot system with XP and Vista on a new hard-drive that replaced my old one which was clearly dying [BSoD and all].
This new format is quite new to me, I am in need of some advice and tips. Insofar as the actual system goes, it is running along very smoothly, I've hunted down all the drivers and everything is behaving normally, but there is one thing that bugs me

Do I have to install each program/service twice [on each OS] so I can use them?

This would be especially problematic for 'library' type of software such as iTunes, as the duplication of media would become absolutely hideous.
Security/Antivirus software would also become a nightmare, as any subscriptions would need to be doubled, which forces me to go back to freeware.

is there such a thing that 'bridges' the programs in either OS?

[excal]

I am now running a dual boot system with XP and Vista on a new hard-drive that replaced my old one which was clearly dying [BSoD and all].
This new format is quite new to me, I am in need of some advice and tips. Insofar as the actual system goes, it is running along very smoothly, I've hunted down all the drivers and everything is behaving normally, but there is one thing that bugs me

Do I have to install each program/service twice [on each OS] so I can use them?

This would be especially problematic for 'library' type of software such as iTunes, as the duplication of media would become absolutely hideous.
Security/Antivirus software would also become a nightmare, as any subscriptions would need to be doubled, which forces me to go back to freeware.

is there such a thing that 'bridges' the programs in either OS?

Unfortunately, no. This would go against the idea of having two separate installations in the first place - to have an isolated (and different) instance of an operating system.

You will have to install applications on both to be able to use them on both.

The best way to approach application installs is to ask yourself why you did this in the first place? Was it to test Vista? If so, install everything on XP and a limited selection to start off with on Vista. Want to use Vista, but a certain application that you need runs only on XP? Install everything on Vista and just that application on XP.

In the latter scenario, you could also use VirtualBox (freeware/GPL) to create a virtual instance of said operating system in your current OS so there is no need to reboot.

A lot of the time, in a dual Windows setup, you'll find that you'll tend to one or the other operating system to the point where one of the two becomes redundant.