XP added to Vista machine for dual boot

Have recently added Vista to 2 XP machines and it went smoothly/quickly. However, I am now trying to add XP to a native Vista PC and I am having an issue (surprise!). On the other 2 PCs, after all was done, whichever OS I booted into saw it's drive as C: and the other OS drive as D:. Both were single drive PCs that had the single drive partitioned into 2. Same with this new Vista PC. I can boot into XP but, when I do, XP sees the Vista drive as C: and the XP drive as D:. This is creatinf havoc trying to load various drivers. Have tryed numerous different configurations of boot.ini to no avail. The only way I can get XP to boot is to have boot.ini/netdetect/ntldr in the root of th Vista drive. This is not consistent with the previous 2 PCs where I added Vista.

Current boot.ini attached

Any thoughts/help would be greatly appreciated.


  • bootini.txt
    231 bytes · Views: 7
Welcome to NST Highmaster.
Here's the gen from Vista Help

Which drive letter will your clean installation of Windows Vista use? That depends on how you install it. If you currently have a working copy of any Windows version on drive C and you install a clean copy of Windows, drive letters are assigned using the following logic:
If you begin the installation process by booting from the Windows Vista media and choose a partition other than the one containing your current copy of Windows, the new installation uses the drive letter C when you start up. The volume that contains the other Windows installation uses the next available drive letter. When you choose the previous Windows installation from the startup menu, it uses the drive letter C, and your new Windows Vista installation is assigned the next available drive letter. In this configuration, you can be certain that your current operating system is always on the C drive, but drive letters assigned to volumes you use for data may shift in unexpected ways.
If you begin the installation process by running Setup from within your current version of Windows and use the Custom (Advanced) option to perform a clean install on a partition other than the one currently in use, the new installation uses the next available drive letter. The volumes containing each installation have the same drive letters regardless of which Windows version you select at startup.

There’s no inherent reason to prefer either of these options over the other. If you prefer the consistency of knowing that all system files and program files are on the C drive, you’ll probably want to choose the first option. If you would rather use drive letters to keep track of which Windows version is running at any given time, you’ll prefer the second option. But either configuration should work reliably with any combination of software, hardware, and settings.

Now that XP has installed that way (like my system), you can't change anything with boot options.
There will be a problem if XP can see a C:\ disk, because some software will insist on putting stuff on C if there's one there.
You can use HnS (Vista Hide 'n Seek) to hide Vista from XP, which you should be doing on all of your dual-boots if you use system restore. (XP destroys Vistas restore points if if can see them)
Like Terry says, it is a matter of how you install it. Otherwise, Vista well consider itself drive C: when you boot it by default. You cannot change drive letters inside of the OSes when they are booted and changing them using some other method may create more problems. So, planning carefully as you install the OSes is key.
Thanks for the quick responses. I installed by booting into the XP CD after I had created the empty partition using Acronis. I assumed that XP setup would see it as C:, but maybe it didn't. I believe I'll try the HnS and see if that will solve the issue. While I like the idea of the active OS using drive "C", I can live with the other method if I can correctly install various software that assumes C: by default.

I'm a bit confused as to why you would be having issues that assume drive C: by default if you are only dual-booting one instance of XP and Vista. Since they consider themselves drive C: when you boot into either of them, installing the software shouldn't be an issue.
You didn't read the post carefully enough Justin. On his 3rd system XP boots as D:\ but sees Vista as C:\.
For the Vista machine, then yes. XP and earlier versions of Windows respect the letter mappings of other installations you have on the machine. Since you can't change them in XP nor Vista, you'll haft to re-install with XP and then Vista.
Using the HnS cured the problem of installing the drivers. Thanks again for the info. I know there are issues with XP screwing up Visat backups. Do I still have to worry about that if I boot into XP with the drive attached (external USB) that contains the Vista backups? Also, I now see OS choices two times. First the GRUB menu, then the windows boot manager menu. Is that normal?
If you use HnS to boot into the external drive, you should be fine.

You can get rid of the second boot menu by using EasyBCD to set the timeout to 0 - just make sure Vista is set as the default in EasyBCD first though!
Any drive on which you install any software from Vista will need to be monitored by Vista's system restore. Turn off system restore monitoring on all the other drives.
Likewise from the XP boot, just monitor drives on which any software for XP could be installed. (They're the drives that system restore will reset things on - monitoring data drives just adds an unnecessary overhead and wastes space on the drive)
Then in HnS, mark all drives with a Vista Restore folder as "Vista", and they'll all be hidden. (It's the restore folders you're really protecting. XP sees them as corrupt (different format) and kindly recreates them for you)
"If you use HnS to boot into the external drive, you should be fine."

Not sure I understand... HnS says to disconnect all external drives before you run it.

"Then in HnS, mark all drives with a Vista Restore folder as "Vista", and they'll all be hidden."

Have looked multiple times for a way to designate drives in HnS. I am running the version from Vista HnS Beta.rar. What am I missing? Also, does this mean I cannot use the same external drive as a data drive for both OSs? (OK, so I do want my cake and eat it too...) If that's the case, I may need to just use a 3rd party backup so I don't have to worry about being able to restore from the native Vista backups.

Thanks again to all for your help.
I stand corrected.. The current HnS build only lists fixed local disks - however, the recent rewrite of the bootloader components has resolve all issues with external drives, so a new build with tentative support for external disks is probably in order.