James Bannan19 December 2007, 4:00 PM
UPDATED | Got a Vista PC and want to install XP so you can dual-boot between them? Here's how to do it, in an easy, step-by-step format.
Page 3 - Now Install Windows XP
When the Windows XP setup reaches the point where you’re prompted where it is to be installed, you’ll see that while XP can see the space we created earlier, it can also see the partition with Vista on it.
You should be able to see the space you reclaimed on the disk earlier which has become "unallocated space".
Create a second partition using the Windows XP installer screen above by selecting the free space on the drive and pressing "C" to create a partition (if prompted, choose NTFS as the file system.)
Irritatingly, XP assigns a drive letter to this partition (C:) which means that it will use the next available drive letter after all the other physical drives have been taken into account.
This means that the system drive of the XP installation won’t be C:.
From XP’s perspective this isn’t really a problem – it’s smart enough to figure out where everything should go – but some applications make assumptions about where they should install to, and can’t cope with a non-standard Windows configuration.
This was also the case with our tutorial on dualbooting Ubuntu and XP, where Ubuntu had been installed first. However in that scenario, even though the XP system drive had a non-standard drive letter, it couldn’t read the Linux partitions so there was no danger of the two systems overlapping. This is not the case with Vista/XP.
Nonetheless, install XP as normal – there’s no need to do anything differently.
IMPORTANT NOTE – after the initial file copy, Windows XP reboots and loads up the GUI-based component of the install. You may get the following error: “A disk read error occurred – press Ctrl-Alt-Del to continue”. This is caused by a corrupt bootloader – click here to see how to fix this problem.
When the system reboots it won’t bring up a boot menu. Although XP recognises the Vista partition it doesn’t recognise Vista itself. This is because the Windows XP bootloader gets installed to the MBR, thus overwriting the Vista bootloader and so Vista can no longer boot - the XP bootloader can't be made to recognise Vista.
When XP loads, open up Windows Explorer and you’ll see something interesting – a C: and (in this case) an E: drive.
The C: drive contains Windows Vista, and as Windows XP can read NTFS partitions, it can browse and modify Vista’s file structure.
More importantly, applications which have installation paths hard-coded into their install scripts rather than using Windows system parameter variables could easily dump files into C: when they should be installing to E:. This isn’t such a great situation - really the optimal XP/Vista dualboot scenario is to install Vista on a pre-existing XP system.