Windows 7: Partition / Extended : Logical Drives

The Windows Master Boot Record (MBR) partition structure supports a total of only four (4) partitions per Hard Disk Drive / Solid State Drive, they can be either 4 Primary partitions or three (3) Primary partitions and a single (1) Extended partition.

This shows the different methods to create an Extended partition wherever you need one so you can create as many Logical drives as there are available drive letters that can be used to install a Windows Operating System or for data storage.

   Warning

As with anything that makes changes to the Windows structure there is always the chance for an error to occur, it would be advisable to make reliable backups to the external media of your choice of any important data, i.e. pictures, music or documents, that you would not want to lose before you make any changes to your system, it is always better to be safe than sorry.

Let's get started!

If there are 3 existing Primary partitions on the HDD / SSD already, the fourth partition created using Windows disk management will be an Extended partition by default.

To view the relevant information on the partition structure, type diskmgmt.msc in the Windows start menu search box, then right click the entry and click "Run as Administrator" if you should get a User Account Control (UAC) prompt enter your user credentials and click Yes.



Method One

This is what I'll be starting with.

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1) Open an elevated command prompt, in the command window that opens type diskpart and hit the <enter> key, all commands are followed by <enter>.

Here are the commands, click the images below to see how they are implemented.

list disk

select disk # (# = target disk number)

create partition extended

exit (2 times to close the command window)

If you need to create a specific size Extended partition, use this command.

create partition extended size=61440 <- 60GB

It has to be entered as MB and 1024MB = 1GB so 1024x60 = 61440

You can create any size you need using the formula above.

2) Now in Windows disk management right click the Extended partition Free Space to create Logical drive(s) as needed, anything created within an Extended will be a Logical drive by default.

You can create as many Logical drives within an Extended partition as there are available drive letters; you can create and name the drives in any way you like, this is just an example.

Method Two

Here's the situation a lot of people are finding themselves in when purchasing a factory built PC these days, a single HDD and all the partitions taken by the manufacturer, leaving no chance of creating any additional partitions.
The fortunate side of a layout like this is the use of the new Windows 7 System Reserved partition and it being the System Volume, where the Windows boot files are stored.

If this is the situation you're in, after you have made back-ups of the data you need to save to external media and created the set of factory recovery disks or better still, created a complete image of the entire HDD to external media that can be restored if the need ever arises, have a look at the information below.

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   Warning

If you do not have the Windows System Reserved or a System Primary partition completely separate from the Windows 7 partition present that is marked as the "System" partition in disk management do not attempt this, if you do Windows will not boot as Windows will not/is not able to boot / start independently from an Extended partition Logical drive, the system boot files must be stored on a Primary partition to execute.

Windows XP users, do not do this or XP will not boot at all.

Start by downloading the Partition Wizard Bootable ISO file from either link below then use the Windows 7 USB/DVD Download Tool to create a bootable DVD or USB flash drive.

Partition Wizard Free Bootable CD

OR

Partition Wizard Bootable Flash Drive

To boot the disk, in the BIOS set the PC boot order to boot first from the CD/DVD or USB drive, insert the PWBD and restart the PC, it'll take a few minutes for it to setup with no input at all from the user needed.
Once the program has started you can remove the CD/DVD or USB if you like.

1) In the Partition Wizard program, right click the Windows 7 partition and click Modify then Set as Logical; then at the top left Action bar click Apply; then click Yes for the conformation dialog box.

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2) You will get a Pending window but that just takes seconds to complete and then click OK for the Successful dialog box.

Then remove the PWBD from the CD/DVD or USB drive and at the upper left corner click General then Exit to close the Partition Wizard program and restart Windows 7.

Restart Windows a couple times before you proceed to make sure all is well.

In the Windows 7 start menu search box type diskmgmt.msc then right click the entry and click "Run as Administrator" if you get a User Account Control (UAC) prompt enter your user credentials and click Yes.

3) In disk management right click the Windows 7 partition and click Shrink Volume you can accept the offered size or you can create a specific size, don't make Windows 7 too small so installed programs/apps have the needed room.

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4) Now right click the new Extended partition Free Space and click New Volume to create the Logical drive(s) one at a time as needed.

It is suggested to restart Windows every time you make a change to let Windows 7 accept the changes to the system without issue.

Enjoy!