Saw an interesting thread on TenForums this morning. It’s entitled “Anyone able to clarify what these 5 partitions are?” And indeed anybody who’s been working with Windows 10 for any length of time can identify them immediately. Here’s an annotated version of the graphic from that very post:
Old-fashioned boot/system disk layouts have one recovery partition at the head and another at the tail.
[Click image for full-sized view.]
Why Do Many Win10 PCs Still Use Old-Fangled Boot Disk Layout?
Short answer: because that’s how the Microsoft Windows installer worked until one of the mid-range builds for 20H1/2004 came out last fall (thanks to the reader whose comment helped me set the record straight: I originallly claimed it was 1909, which was incorrect). And those whose disks are already laid out this way will stay this way unless they do a clean install. Two older Win10.Guru posts explore this topic in some detail. First, there’s Kari’s November 13, 2019 post entitled Thank you, Microsoft – An Important Change in Windows Setup. Second, there’s my own December 2 post entitled New 1909 Disk Layout. What makes the foregoing screen cap a bit weird is that the poster somehow munged his new recovery partition at the right-hand side of the disk layout shown. If you read through the post, you’ll get a tutorial on using the reagentc command to restore and reset the recovery partition appropriately.
Anybody who’s been upgrading Windows 10 since before 1909 emerged in Fall 2019 will probably use the same disk layout shown above. My production PC actually has 6 partitions because it’s on an NVMe SSD that Samsung Magician manages. Consequently, it uses an addition 50-plus GB for “overprovisioning.” (That means spare, empty disk space that can take over for other disk blocks showing signs of impending or actual failure; it appears as the lead-in graphic for this story.) But if you do a clean install of 1909 or later versions, the layout sequence will omit a Recovery partition in spot #1, and Run in this order: EFI-MSR-Win10-WinRE instead. And that’s the way we like it!
[Note] The lead-in graphic for this story comes from the Disk Management (diskmgmt.msc) console in Windows 10. The second image originates from Macrium Reflect. Unlike the Disk Management console it shows the MSR partition in all its glory (DiskMgmt.msc omits it completely). Thanks to CountMike for reminding me of this.
Author: Ed Tittel
Ed Tittel is a 30-plus-year computer industry veteran. He’s a Princeton and multiple University of Texas graduate who’s worked in IT since 1981 when he started his first programming job. Over the past three decades he’s also worked as a manager, technical evangelist, consultant, trainer, and an expert witness. See his professional bio for all the details.