Yes,it COULD be done,but.......since you have only one SATA cable,only one
drive's data contents can be accessed by the system at any given point of
time.
And therefore,as a result,there is no way the system can simultaneously
detect the presence/existence of two operating systems.
Since you installed each OS individually,it is confirmed that XP's NTLDR had
only one entry (of it's own) in it's boot menu and the same happened with
Vista's BCD.None of them `know` that the other exists in the same
system,since there is no way you can MAKE them know by using just one SATA
cable.There leaves no scope for tinkering with boot-loaders.
No,the boot-loader cannot meddle with the BIOS.Only you can,by entering the
setup at the POST(Power-On Self-Test) screen.You do not have to add entries
to anything in the BIOS but to the boot-loader's
configuration...............and the boot-loader itself would reside on a
hard-disk drive,only one of which can be accessed at a time in your
situation.Simply because the two hard-disks have different power cables
wouldn't do the job.Different SATA data cables too would be needed.
I was in a somewhat similar situation just about a month ago when I needed
to work with XP for my academic project.However,my case was much easier
since my installation of XP was on a PATA hard-disk,the data cable for which
would be obviously different from SATA ones and therefore both drives could
be simultaneously accessed.
PLEASE get another data cable(SATA) for accessing your other hard-disk
without having to meddle with the chassis.
"Keen Lam" <> wrote in message
news

B04A008-888C-41F3-8B00-...
Thanks. At least I know that it can be done.
I installed each OS separately on separate HD and only connect one SATA
cable at a time. I am not too familiar with using boot-loader tools. I've
just looked up some boot software and found one called VistaBoot Pro. Can
this be used to set up the BIOS instructions, ie add the entries to make
this
happen?
I wonder if there are any other Vista users in the same situation.
"Hiren" wrote:
> Which operating system did you first install and was it detected while you
> installed the other one?
> Do you use any other boot-loader other than NTLDR or BCD?
> The BIOS must be giving you an option to change the order of hard-disks
> searched while searching for a boot-able device.In the BIOS setup,have a
> look at the options under the `Boot` menu.You can change that anytime you
> want to go back to XP so that your hard-disk containing XP is looked at
> first and revert the change after your work is done without having to open
> up the chassis.But this too is a bit inconvenient,so assuming that you
> have
> more than one SATA cable with you,you will have to add the entry for
> booting
> XP in Vista's boot-loader(i.e.,BCD).
>
> "Keen Lam" <Keen > wrote in message
> news:6DB9CC1C-F2BB-4750-8457-...
> I have fully licensed copies of Vista and XP on separate HD on the same PC
> and I have to physically swop the SATA cable inside the PC to boot. I
> still
> have some Vista incompatible software on XP that I have to use from time
> to
> time.
>
> Can I set this to boot from the PC then select which OS to use?
>
> Vista SP1 has been installed. Appreciate any advice as the cable
> switching
> is a bit of a pain.
>