Windows

Slideshow: Shrink a hard drive volume in Windows 7

Open the Disk Management Tool with administrative rights

Microsoft Windows 7 provides several tools for managing the configuration of your computer and the various parts of your operating system. There are times where you will want to shrink the amount of allocated space on your hard drive, referred to as a volume, to make room for another partition. In the not so distant past you would have used a third-party tool for this task, but with the Windows 7 Disk Management Tool the utility you require is part of the operating system.

Shrink a volume
The first step is to start the Disk Management tool with elevated administrative rights. Click the Start Menu Button and type diskmgmt.msc into the search box and then right-click the diskmgmt.msc entry to get to the Run as administrator item in the context menu as shown.

This gallery is also available as a TechRepublic blog post and download. Image created by Mark Kaelin for TechRepublic.

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Mark Kaelin is a CBS Interactive Senior Editor for TechRepublic. He is the host for the Microsoft Windows and Office blog, the Google in the Enterprise blog, the Five Apps blog and the Big Data Analytics blog.

6 comments
joe
joe

I'm running Windows 7 Home Premium, Service Pack 1, v.721 On my system the program is "disk management" - type this in the Startup Search Box rather than diskmgmt.msc.

parnote
parnote

Mr. Kaelin uses bad math to determine the size of the new partition, at least as far as the OS is concerned. Mr. Kaelin uses the figure used by disk manufacturers (1,000 bytes = 1 KiB, or 1,000 MB = 1 GB). Disk manufacturers are the ONLY ones who use these figures, so they can artificially boast that the size of the hard drive is larger than what your computer will see it as. Your OS sees it differently, since it uses a binary system, and not a Base 10 numbering system. Thus, your operating system sees 1024 bytes = 1 KiB, and 1024 MB = 1 GiB, instead of using the disk manufacturer's figure of 1,000. Thus, if Mr. Kaelin wanted to make a REAL 5 GB "new" partition, the size he should have entered in the new size box should have been 5,120, not 5,000. Hence, this is the reason his new partition is reported as 4.88 GB, and not 5.00 GB, which it would be if he has used 5120 MB as the size of his new partition. Do the math: 5,000 / 1024 = 4.88, and 1024 x 5 = 5120. Also, the Windows file system (or any file system for that matter) has NOTHING to do with the lowered reported size of the partition, and EVERYTHING to do with the bad math that Mr. Kaelin used. Since it is a new partition, and labeled as "Unallocated," there is no file system on the new partition, so therefore, the Windows file system could NOT be taking up any space at all. Unallocated partitions will have to first be formatted to be utilized, and not until then will there be any loss of space on the new partition.

screwe
screwe

"The actual size will be less than what you asked for as their will be some space taken up by the Windows file system." The reason it's showing as 4.88GB rather than 5.00GB is because you put 5000MB. From experience (haven't checked documentation to confirm) I'm pretty sure windows works on 1024MB per GB, not 1000MB like HDD manufacturers etc. If you had popped in 5120MB (5x1024) it'd show as (or v. close to) 5GB. Whereas 5000/1024 = 4.88.

paul
paul

wow ... just like dos ...that is a step forward.. I am amazed the search functionality found it as well... regards fitvideo

jhanevd
jhanevd

just want to clarify is this is not really possible for the hard drive volume with operating system?

hello2012
hello2012

You can shrink system volume on Windows 7 through the built-in disk management, but there is some limitations fret you do perfectly. The most efficient way is use 3rd party tool like Partition Assistant. Its free windows 7 partition manager gives a hand do such jobs when your OS is 32 bit. If your OS is 64 bit, professional also gives you a hand.