SOLVED: Windows 10 Hard Drive Partitions Explained In Simple Terms

A disk “partition” is just a logical slice of a hard drive.  Logical means that you still only have a single drive but it is virtually cut into pieces so that if one partition has a problem, the whole disk will not fail.

Let’s look at each of the different partitions you are likely to see on a hard drive running Windows 10 or Windows Server:

Windows 10 Partitions Explained


1- What is the RECOVERY Partition?

The Recovery Partition is a a very small amount of hard drive space that contains a limited set of Windows 10 installation files and a very stripped down interface called the Windows Recovery Environment (aka WinRE).  It is only used when the system detects corruption on the hard drive.

Can the Recovery Partition be Deleted Safely?

Yes, but generally you should not delete the Recovery Partition because:

  1. doing so will not give you very much additional space, just .5GB
  2. from that point on you will have to source a Windows 10 DVD or USB stick IF the system needs to replace damaged operating system files

Why Do I Have Two (or more) Recovery Partitions?

Every time Windows upgrades to a new version (twice per year as of 2020), the upgrade process will evaluate the empty space in your Recovery Partition and determine if there is enough space for it to add the new recovery files.  If there is not enough free space the Window 10 upgrade process will automatically shrink your Primary Partition, create a new Recovery Partition and add its files there.

Can Extra Recovery Partitions be Deleted Safely?

Yes, old recovery partitions can safely be deleted as they are being ignored by the system and just wasting space.  The recovery partition furthest to the immediate RIGHT of your Primary Partition (i.e. C:\) is the active one and all others can be safely deleted.

can recovery partitions be deleted safely


2- What is the SYSTEM Partition?

A Windows 10 System Partition is the place where “boot” files are stored including the Windows Boot Manager, Boot Configuration Data (BCD) Store and if your hard drive is encrypted the System Partition is where encryption information is stored.

Can the System Partition be Deleted Safely?

No, definitely not.  If you were to remove the System Partition, your data files would NOT be lost but you would no longer be able to boot (start up) the operating system.


3- What is the MSR (RESERVED) Partition?

M.S.R. is an acronym for “Microsoft Reserved” and it is the place Microsoft leaves as a safety valve for future use.  If Windows disk management tools detect problems with parts of your physical hard drive storage, it will use move the data from the damaged parts of the disk to a the MSR area.

Note that while the vast majority of Windows 10 computers will have an MSR partition, some will not.  MSR only appears on GPT formatted UEFI systems.

Can the MSR Partition be Deleted Safely?

Yes, in most situations the MSR Partition it can be deleted.  However you should not delete the Recovery Partition because:

  1. doing so will not give you very much additional space, just .1GB (usually)
  2. if files are stored in that partition you will loose them and that will cause corruption

4- What is the PRIMARY Partition?

The Primary Partition on a Windows 10 PC is is the drive space you see when you look in COMPUTER / FILE EXPLORER which almost everyone has configured with drive letter C:\ .

Can the Primary Partition be Deleted Safely?

No, definitely not.  If you were to remove the Primary Partition, your data files, the operating system and all your programs would be lost.


 

Questions or Comments?