I use Windows Vista and want to install Windows 7 on a separate partition. I decided to shrink my D: volume, so I could create a new partition to install the new operating system.

I use these instructions:

Control Panel -> System and Maintainence (skip this one if you're in Classic view) -> Administrative Tools -> Computer Management. Once you launch the Computer Management tool, click on Disk Management under the Storage heading in the sidebar. It's partitioning time.

I freed up 17,38 GB of space that is now shown as 'unassigned'.

Now I click "New Simple Volume". After I'm done with the wizard (size, drive letter etc.), it shows me a warning message. I translated it from Spanish:

The chosen operation will convert all selected basic disks into dynamic ones. If a disk is converted into dynamic one, you will not be able to boot any operating system from it, except for a current starting(?) volume. Are you sure you want to continue?

  • If I decide to agree, does it mean that I will be unable to boot Windows 7 from this new partition?
  • Which drives are 'selected'? Only this one that I am going to create?

Spanish is not my native language, and I was unable to Google anything with the data I have.

I have only seen a related question for Windows 7:

  • You could try a liveCD like Parted Magic to create the partition. – Rob Sep 21 '11 at 19:59
  • Do you have any other "New ..." options besides 'simple volume'? Could you post a screenshot of your current Disk Management setup? – grawity Sep 21 '11 at 20:42
  • A screenshot of the warning message in Spanish, just for the record: i52.tinypic.com/2s6vp5h.png – sdk Sep 21 '11 at 21:49
  • @grawity here is the Disk Management screenshot: i54.tinypic.com/23v1hck.png Only 'new simple volume' is accessible; two other options are inactive. – sdk Sep 21 '11 at 23:31

How many existing Primary Partitions exist on the drive (before the one you are trying to make)?

(This can/does include the System Reserved partition, the main Windows partition, any OEM recovery and/or tools partitions, etc.).

You can only have a max. of 4 (or 3 primaries and one extended) on a Basic disk, and if you try to go over 4 it can/will give you this (or other) misleading messages instead of just telling you that you can't have more than 4.

The reason for this weirdness seems to be because normally if you have 3 primary partitions and you attempt to create a 4th "Simple Volume" on a Basic disk, Windows Disk Manager will automatically create an extended volume taking up all the contiguous free space in the area you specified, with a logical partition/volume inside of that at the size you specified, instead of a 4th primary.

If you already have 4 primaries, it doesn't quite know what the "real deal" is, and gives you the weird/wrong message.

  • "Simple Volume" is not the same as "primary" -- it's a partition type for Windows "dynamic disks", a proprietary LVM-like function. Windows is probably offering to get around the four-primaries limit by converting the disk to "dynamic". – grawity Sep 21 '11 at 20:44
  • @grawity I realize "Simple Volume" is not the same as a a primary. In the Disk Manager the option is "New Simple Volume" (or New Spanned Volume, or New Mirrored Volume, etc.) when you go to create a partition. It doesn't offer anything about dynamic or basic during that wizard (as the disk type is already chosen when it was first setup/partitioned). If you have 3 primaries, on a basic disk type, and you run that "New Simple Volume" wizard again, it makes an Extended Partition out of all available space, and makes a logical volume inside that the size of the partition you specified. – Ƭᴇcʜιᴇ007 Sep 21 '11 at 21:04
  • Indeed, it seems that I already have four primary partitions. Two for EISA, one for Windows Vista and one for my data. Screenshot: i54.tinypic.com/23v1hck.png (G: is an external HDD) Apparently, there is no way to install Windows 7 on my laptop hard disk? – sdk Sep 21 '11 at 21:44
  • @sdk Yes, you could stretch one of the partitions (back) out and then create a VHD on it, you could then install Windows 7 to that 'drive' by manually mounting it during Win 7's setup. – Ƭᴇcʜιᴇ007 Sep 22 '11 at 2:55

I would suggest you download "EaseUS Partition Manager" http://www.partition-tool.com/download.htm. It is fast and powerful and will allow easy resizing and allocation of your partitions on a live system.

Your data partitions do not need to be primary partitions - there is no operating system installed there. Take things one step at a time and move your data to logical drives in an extended partition first. I would highly recommend making a backup of your entire drive before beginning any operation as major as this will become. There are many programs around, my personal favourite is Acronis, but there are good free alternatives.

You can have up to 4 partitions on a disk, e.g. maximum of 4 primary partitions, or maximum 3 primary partitions and/or 1 extended partition. These are described by one partition table (4 by 16 bytes - hence the 4 partition limit) in the Master Boot Record (MBR).

Only one of these primary partitions may be "Active", this is the "system partition" which is where all of the operating systems loader programs are stored.

The extended partition can contain multiple "logical" drives, limited only by the number of letters in the alphabet (in DOS based OSs) and disk space. Each of these drives has an Extended Boot Record (EBR) associated with it. You cannot make any of these drives "active".

Older operating systems like MSDOS and Windows 98 etc MUST be installed in a primary partition - indeed they had to be installed on the first primary partition.

Later operating systems (XP, Linux, etc.) can be installed in any partition but the boot files MUST still be located on the active primary partition.

There MUST be at least one active primary partition if the drive is to be "bootable". Sector 0 of this active partition is where the boot program is stored (the boot sector).

The BIOS runs a bootstrap program which reads the MBR. The MBR program reads the partition table and looks for the system partition. The MBR then loads the boot sector program, which then reads the required operating system starter files, which themselves begin to load the relevant operating system... which may or may not reside on another partition or indeed on another drive.

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