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Partition shift w Dual boot XP/Win7

Discussion in 'Windows 7' started by Eric, Apr 4, 2010.

  1. Eric

    Eric Flightless Bird

    I've installed Win7 to D: on a machine that already had XP on C:. I
    was sSurprised to find that when the machine rebooted to Win7, the
    Win7 partition was now C: and XP was reassigned to D:

    That's not the case when setting up two XP partitions on one
    machine--the 2nd will boot from, and stay on, drive D:

    Initially I didn't like the partition shift, but I realized that there
    are places where I need that to happen. Does anyone know if Win7
    always does the partition shift, or was that the result of the way it
    was installed? Any way to force that to happen?

    Also, do the two bootable partitions just exchange drive letters
    (bootable E->C, D->D, C->E), or are they going to sort of rotate?
    (bootable E->C, C->D, D->E)

    I ask because one system has XP on C:, with immovable data on D:. I'd
    like to install Win7, but need to make sure the D: partition doesn't
    shift. If I install Win7 to E:, if the above holds, I presume that it
    will 'rotate' the D: drive to E: (as above). I'd like to keep D:
    stationary.
     
  2. c_atiel

    c_atiel Flightless Bird

    Drive letter assignments are generated by the OS, they are not hardwired
    into the hard drive.
    When you boot into XP it should see itself as the C drive because otherwise
    programs installed in XP will not work as they are looking for files
    scattered on the C drive-dlls and the like. The Win 7 partition/hard drive
    will be assigned another letter by XP. When you boot back to Win 7 it will
    again see itself as the C drive, or whatever drive letter Win 7 assigned
    itself at installation, which does not have to be C.
    When you are working in Win7 you cannot use programs installed on XP unless
    you have also installed them in Win 7. Therefore it does not matter what
    drive letter Win 7 assigns the XP hard drive/partition when you are working
    in Win 7.
    Win 7 installs a different boot loader than XP and installs it on whichever
    drive your BIOS recognizes as the first hard drive to look to for an
    operating system, presumably the hard drive that held XP in your case.
    Dual boot installations, as long as you installed XP first, are pretty
    reliably set up correctly automatically when you then install Win 7.
     
  3. Eric

    Eric Flightless Bird

    On Sun, 4 Apr 2010 15:40:20 -0700, "c_atiel" <fac_187@hotmail.com>
    wrote:

    >Drive letter assignments are generated by the OS, they are not hardwired
    >into the hard drive.


    Yes, I know.

    >When you boot into XP it should see itself as the C drive because otherwise
    >programs installed in XP will not work as they are looking for files
    >scattered on the C drive-dlls and the like. The Win 7 partition/hard drive
    >will be assigned another letter by XP. When you boot back to Win 7 it will
    >again see itself as the C drive, or whatever drive letter Win 7 assigned
    >itself at installation, which does not have to be C.


    Well, that is the main question. I've installed lots of dual boots
    with XP on both partitions. In that case, as I mentioned, the XP on D:
    stays on D: when it's booted.

    By contrast, the recent XP/Win7 dual does indeed shift the partitions.
    XP was installed on C:. I later installed Win7 to D:.

    When I boot to Win7, which I expected to be on D:, it was actually on
    C: (and the XP partition was shifted to D:). That's the difference in
    behavior.

    My question: Is that always going to occur when Win7 is installed to a
    machine previously running XP? How to you assure that it does happen?

    (BTW, the q is in regard to a laptop. Just one large drive, with 3
    partitions. XP already installed on C:)
     
  4. Eric

    Eric Flightless Bird

    On Sun, 04 Apr 2010 15:25:38 -0400, Eric <Eric@---nospam---.com>
    wrote:

    >I've installed Win7 to D: on a machine that already had XP on C:. I
    >was sSurprised to find that when the machine rebooted to Win7, the
    >Win7 partition was now C: and XP was reassigned to D:
    >
    >That's not the case when setting up two XP partitions on one
    >machine--the 2nd will boot from, and stay on, drive D:
    >
    >Initially I didn't like the partition shift, but I realized that there
    >are places where I need that to happen. Does anyone know if Win7
    >always does the partition shift, or was that the result of the way it
    >was installed? Any way to force that to happen?
    >
    >Also, do the two bootable partitions just exchange drive letters
    >(bootable E->C, D->D, C->E), or are they going to sort of rotate?
    >(bootable E->C, C->D, D->E)
    >
    >I ask because one system has XP on C:, with immovable data on D:. I'd
    >like to install Win7, but need to make sure the D: partition doesn't
    >shift. If I install Win7 to E:, if the above holds, I presume that it
    >will 'rotate' the D: drive to E: (as above). I'd like to keep D:
    >stationary.


    Now that I think about it, it only matters that the Win7 partition
    shifts to C: when Win7 is booted. I can change the drive letters of
    the non-active partitions via DiskManager.

    So I'm hoping to install Win7 to E:, and get that partition to shift
    to C: when it's booted.

    As noted, this is for a laptop, with 3 partitions on one large drive.
     
  5. peter

    peter Flightless Bird

    So your aiming to run 1 installation of XP and 2 Installations of W7???
    Do you have 2 copies of W7? if not what you are propsosing is against the
    EULA and you might not be able to activate that 2nd install of W7.

    peter

    --
    If you find a posting or message from me offensive,inappropriate
    or disruptive,please ignore it.
    If you dont know how to ignore a posting complain
    to me and I will be only too happy to demonstrate :)


    "Eric" <Eric@---nospam---.com> wrote in message
    news:6geir5pjdolirtmpgudhf520h3hmhim6cf@4ax.com...
    > On Sun, 04 Apr 2010 15:25:38 -0400, Eric <Eric@---nospam---.com>
    > wrote:
    >
    >>I've installed Win7 to D: on a machine that already had XP on C:. I
    >>was sSurprised to find that when the machine rebooted to Win7, the
    >>Win7 partition was now C: and XP was reassigned to D:
    >>
    >>That's not the case when setting up two XP partitions on one
    >>machine--the 2nd will boot from, and stay on, drive D:
    >>
    >>Initially I didn't like the partition shift, but I realized that there
    >>are places where I need that to happen. Does anyone know if Win7
    >>always does the partition shift, or was that the result of the way it
    >>was installed? Any way to force that to happen?
    >>
    >>Also, do the two bootable partitions just exchange drive letters
    >>(bootable E->C, D->D, C->E), or are they going to sort of rotate?
    >>(bootable E->C, C->D, D->E)
    >>
    >>I ask because one system has XP on C:, with immovable data on D:. I'd
    >>like to install Win7, but need to make sure the D: partition doesn't
    >>shift. If I install Win7 to E:, if the above holds, I presume that it
    >>will 'rotate' the D: drive to E: (as above). I'd like to keep D:
    >>stationary.

    >
    > Now that I think about it, it only matters that the Win7 partition
    > shifts to C: when Win7 is booted. I can change the drive letters of
    > the non-active partitions via DiskManager.
    >
    > So I'm hoping to install Win7 to E:, and get that partition to shift
    > to C: when it's booted.
    >
    > As noted, this is for a laptop, with 3 partitions on one large drive.
     
  6. Eric

    Eric Flightless Bird

    On Sun, 4 Apr 2010 20:33:50 -0600, "peter" <peter@nowhere.net> wrote:

    >So your aiming to run 1 installation of XP and 2 Installations of W7???
    >Do you have 2 copies of W7? if not what you are propsosing is against the
    >EULA and you might not be able to activate that 2nd install of W7.
    >
    >peter


    Nope, only one of each. And I have multiple licenses for both anyway,
    so that's not the issue.

    Any ideas about the original question?
     
  7. Andy

    Andy Flightless Bird

    The rule is, when you boot from the DVD to install, the partition in
    which you install Windows 7 is set to C:, and the system partition,
    which would be C: in XP, is set to D:. If you install Windows 7 from a
    running Windows XP, then the drive letters for Win7 will be the same
    as XP's. This behavior started with Vista.

    On Sun, 04 Apr 2010 15:25:38 -0400, Eric <Eric@---nospam---.com>
    wrote:

    >I've installed Win7 to D: on a machine that already had XP on C:. I
    >was sSurprised to find that when the machine rebooted to Win7, the
    >Win7 partition was now C: and XP was reassigned to D:
    >
    >That's not the case when setting up two XP partitions on one
    >machine--the 2nd will boot from, and stay on, drive D:
    >
    >Initially I didn't like the partition shift, but I realized that there
    >are places where I need that to happen. Does anyone know if Win7
    >always does the partition shift, or was that the result of the way it
    >was installed? Any way to force that to happen?
    >
    >Also, do the two bootable partitions just exchange drive letters
    >(bootable E->C, D->D, C->E), or are they going to sort of rotate?
    >(bootable E->C, C->D, D->E)
    >
    >I ask because one system has XP on C:, with immovable data on D:. I'd
    >like to install Win7, but need to make sure the D: partition doesn't
    >shift. If I install Win7 to E:, if the above holds, I presume that it
    >will 'rotate' the D: drive to E: (as above). I'd like to keep D:
    >stationary.
     
  8. Eric

    Eric Flightless Bird

    On Mon, 05 Apr 2010 00:29:52 -0700, Andy <1@2.3> wrote:

    >The rule is, when you boot from the DVD to install, the partition in
    >which you install Windows 7 is set to C:, and the system partition,
    >which would be C: in XP, is set to D:. If you install Windows 7 from a
    >running Windows XP, then the drive letters for Win7 will be the same
    >as XP's. This behavior started with Vista.


    Excellent! That answers that.

    On the first system, I could have sworn that I installed Win7 via XP
    rather than booting the DVD, but I must have misremembered. Good
    thing I asked.

    Thanks, Andy.
     

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