First of all I believe XP 32bit is better for games...but its your choice.
Check your BIOS and see if it will let you pick which HD to boot from by
means of an F key during the boot process.This way you dont need a
"software" dual boot.
In order to create the dual boot I describe you disconnect the drive that
Vista is installed on and proceed with a normal XP installation.This keeps
each OS boot files on their respective drives.Once you have XP setup to your
satisfaction you reconnect the Vista drives and upon boot use the F function
to pick which drive(OS) to boot from.
If your BIOS does not support this option you would need to enter the Bios
and set the boot order accordingly.
Since there is no cross referencing of OS's on the MBR on any of the 2
drives it is very easy to undo the "dual" boot...remove/format the OS no
longer needed.
here is a website that explains the "software" Dual boot.........read down
till close to the end.you wont need the diskpart instructions.
http://apcmag.com/5485/dualbooting_vista_and_xp
peter
"Kev" <Kev@discussions.microsoft.com> wrote in message
news:EAEC9EC0-2D0F-4DBD-B19D-32FF96886306@microsoft.com...
> So ho do i make vista 'not see' the second hard drive, and for that matter
> not let XP see my vista drive?
>
> -kev
>
> "Paul Randall" wrote:
>
>>
>> "Kev" <Kev@discussions.microsoft.com> wrote in message
>> news:52398BDE-49A6-4A12-BBEC-5F101A2173E8@microsoft.com...
>> > Hi,
>> > I am a keen gamer and although i love vista the compatability problems
>> > mean
>> > that i may need to set up dual boot.
>> >
>> > I have Vista home premium 64bit on my C drive right now.
>> >
>> > I plan to get another drive, get XP 64bit, instal it on that hard drive
>> > and
>> > have a dual boot sytem to allow me to play games i can't play right
>> > now.
>> >
>> > I have tried reading up but most of the info talks about dual boots
>> > with
>> > XP
>> > first or on partitions rather than seperate hard drives and talks about
>> > having to repair vista.
>> >
>> > So my question is: how would i set up my pc to have Vista on one drive
>> > and
>> > XP on the other and essentialy just have a start up menu to choose
>> > which
>> > one
>> > i want to use on that login?
>> >
>> > My logic states just instal on seperate hard drives and all things will
>> > be
>> > fine, but reading up it seems not the case, so basicaly HELP! 
)
>> >
>> > Any advice or help would be appreciated
>>
>> I haven't tried this, but perhaps it would work.
>> With only one drive connected, install Vista. After doing your typical
>> setup configuration of first boot-up as a user, shutdown and connect the
>> second drive. On startup, as soon as you have control, remove the drive
>> letter from the second drive, so your Vista only sees the drive it is
>> installed on. Install WXP on the second drive, using a similar
>> procedure.
>> Each time at boot up, hit the function key that allows selecting which
>> drive
>> to boot from.
>>
>> I'd be interested in hearing if this actually works and keeps the systems
>> separate so that both system's recovery stores work.
>>
>> -Paul Randall
>>
>>
>>