Need to change "system" drive letter


I have successfully set up my system to triple boot into 7 and two XP installations. One of those XP installations I like to keep clean (it's for music production) and I was unhappy with it.

So, instead of trying to install XP from scratch I dropped a clean installation of XP into the partition using Paragon and used Easy BCD to create a new entry to point at it.

So far so good... except that this new installation sees the "system drive", the one with Windows 7 (and I presume the various boot files) on it as being the D drive and I would like to keep that letter for the data drive common to all the OSs.

Even though D is not the drive XP is installed on - that is C and Windows sees that as the "Boot drive" - Windows will not allow me to change the drive letter of the "system drive". I'd like to change it to something out of the way such as Z or even hide it completely because when I'm running XP I should never need to go anywhere near the Windows 7 partition.

Anyone any ideas as to how I might do that?
EasyBCD > BCD Backup/Repair > Change boot drive will copy the boot files to the target destination and set it active.
Make that XP and reboot and XP will be "system".
Change your non-system drive letters to your preferred scheme, then set W7 active again (the original boot files are all still there) and reboot.
When W7 is "system" again, you can delete the \boot folder and bootmgr copies from XP.

A thousand thanks for that and many thanks too for the quick response. It worked perfectly so now, on my music workstation, my data drive is D, the DVD is on E, the card readers follow on from that and and the other two installations are tucked out of the way down at Y and Z... lovely. Just when I was preparing myself for having to install it all again.

What you're doing answering my technical questions at half past midnight though doesn't bear thinking about... or were you just killing time waiting for a batch of scones to come out of the oven? :^)

While I think about it, is there any reason why I need to change the boot drive back to the W7 partition? It seems to work just fine with the boot partition as the XP one - in other words stopping after the step when I changed all my XP drive letters. Just wondered if there are any advantages to one over the other.

Nice pic by the way. I believe FX-M is still flying


Aha! There is a reason to change the Boot Drive back. I just tried to boot into the original XP and I noticed a very quick (so quick I had not noticed it before) message saying "Invalid Boot.ini" or something similar and it booted into the Music installation instead (which happens to be the first partition on the drive).

I'm quite sure you could probably direct me to fixing that while leaving the Boot Drive alone but (a) I don't realy mind where the Boot Drive is and (b) putting the Boot Drive back where it was on the W7 partition has cured it so I'm very happy.

I don't know where I'd be without EasyBCD - well some way distant from a working triple boot system that's for sure. Many thanks for your help.

A donation is already on its way.
Last edited:
You should be able to get rid of the Invalid Boot.ini message by adding a new XP entry in EasyBCD and ticking the "autodetect drives" checkbox. You can then delete the old XP entry.


(regardless of whether you change the boot drive or not)
Last edited:
Glad you're OK now Simon.
When I did this sort of thing for a living, I always preferred the end of the working day to get stuff done.
When all the end-users had gone home and stopped phoning for help, and the mainframes were less busy, I could get a day's coding and testing done in a couple of hours. These days, there's no competition for machine time, but I've been spending the last couple of weeks of days and evenings building bookcases, and the wee-small-hours are generally when I get online to kill a few spammers and answer the odd question or two. I've always been of the Owl persuasion rather than the Lark.