Why can't the Win 7 installer see my new hard drive? Please read below?

l need to re-install Win 7 and I want to put it on a larger drive. I don't want to reformat & reinstall on the old drive.

I installed the new drive and used Disk Management to format it in NTFS and it seems to work properly. Then I powered the system down, disconnected the old drive and rebooted from the Win 7 CD with only the new drive connected.

The Win 7 installer says I have no drives and asks for installation media.

When I tried to use DiskPart during the install it saw the drive but said that there was no space on it. There was plenty of space when I tried it out in Windows.

When I booted from the CD with both drives connected the Win 7 installer saw both of them. So for some reason the installer needs to have the old drive installed in order to see the new one. I don't want to install Win 7 on the new drive while the old one is still installed and then have some weird dual boot situation that I have to fix later.

Apparently this topic was discussed at length in the forums a few years ago and I couldn't find any definite fix for it. And nothing recent.

Is there a fix for this that an amateur like me can do? Could a professional shop do this for me?


I already did all the things suggested in the two responses before I submitted the question. And a whole lot more. I even went so far as booting from the Windows XP cd, partitioned & formatted the new hard drive that way. The I installed XP and it was working fine. Then I booted from the Win 7 disk and the installer could not see any drive.

I can't remember exactly how I installed Win 7 on this computer 3 years ago. But I think I must have used a Win 98 start up floppy disk, used FDisk to prepare the hard drive and then booted the Win 7 disk from the DOS commands on the floppy.

I have been reading about this particular issue. Forums are full of unanswered questions and suggestions that do not work. I am beginning to think that my 6-year-old motherboard is the problem but it works prefectly in every other way.

I still seem to have the option of booting from the Win 7 disk, reformatting & re-installing on to the existing hard drive. But I want to know why my system c

2 Answers

  • 8 years ago
    Favorite Answer

    when you unplug the old HDD

    plug the new HDD into that same SATA Port the old HDD was plugged in to

    some machines freak when Port 0 is not connected

    when you boot the win7 install CD and use Diskpart

    do the following

    > list disk

    > select disk n (n is the number given by list disk)

    > clean

    > create partition primary size=MB

    use size=MB if you aren't using the whole HDD for C:\

    size=64000 for 64GB

    size=120000 for 120GB


    if you are using the full size of the HDD then write it without the size=MB

    > create partition primary

    only create the first partition if you are planning on dividing the HDD

    then continue with the installation


  • TWB
    Lv 7
    8 years ago

    Using the old drive, go back and remove the partition you put on the new drive completely. I have seen Windows installer not work on some drives that already have a partition and been formatted.

    Source(s): TWB 35+ years of experience in the service industry. You name it, I have probably fixed it. I did not design it, I did not build it, I did not break it, but I am the one who can fix it. What that means is that I have spent a life time taking these things apart and seeing how they are made. The difficult we do right away, the impossible just takes a little longer. I hear voices, so please be quite so I can listen to them.
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