A quick tutorial on Windows partition types

Topic

New Reply

---

Field Notes

A quick tutorial on Windows partition types

By Tracey Capen A recent reader letter lamented the accidental deletion of a critical PC partition. The event rendered the machine unbootable. It’s easy to get confused about Windows partition types. Here’s a refresher.

---

The full text of this column is postedat windowssecrets.com/best-practices/a-quick-tutorial-on-windows-partition-types/ (opens in a new window/tab).

Columnists typically cannot reply to comments here, but do incorporate the best tips into future columns.

Reply | Quote

Replies

I ran into an issue that I could use some help with:

I copied my GPT UEFI System Reserved partition into my C: Drive, so I only have one partition. Now Windows 10 update 1511 won’t install.

Attempted recovery steps:
I tried recreating a new GPT UEFI parition with command line tool at the beginning of the drive. Then I changed the UEFI to boot from the new boot partition, but no dice.

How this happened:
I had a laptop with two hard drives. (I couldn’t just remove one at install time as are very hard to remove.) I installed Windows 10 with both drives installed. I chose for the O.S. to be installed on my SSD which it did, but it installed the System Reserved on the other standard spinning platter HD. I didn’t want them on separate drives, so I used a partition tool to copy the System Reserved partition to C: drive partition of the SDD hard drive. Windows 10 then booted fine with all partitions on one physical drive.

Question:
Would a solution be to copy the GPT UEFI files from the C: drive to a new blank Fat32 partition? (And erase the one above that I manually created in my fail attempt above?) If so, how do I copy those files, as they are scattered on the C: drive somewhere…

Reply | Quote

Solved the issue by reading more about partitions. Although I had created a new System Reserved partition on my SSD using the appropriate commends, I figured out that I needed to make the new system reserved partition “Active” and removed “Active” status from the Windows partition.

This was the key to understanding partitions:
https://www.partitionwizard.com/partitionmagic/accidentally-marked-drive-c-active.html

Reply | Quote

I ran into an issue that I could use some help with:

I copied my GPT UEFI System Reserved partition into my C: Drive, so I only have one partition. Now Windows 10 update 1511 won’t install.

Attempted recovery steps:
I tried recreating a new GPT UEFI parition with command line tool at the beginning of the drive. Then I changed the UEFI to boot from the new boot partition, but no dice.

How this happened:
I had a laptop with two hard drives. (I couldn’t just remove one at install time as are very hard to remove.) I installed Windows 10 with both drives installed. I chose for the O.S. to be installed on my SSD which it did, but it installed the System Reserved on the other standard spinning platter HD. I didn’t want them on separate drives, so I used a partition tool to copy the System Reserved partition to C: drive partition of the SDD hard drive. Windows 10 then booted fine with all partitions on one physical drive.

Question:
Would a solution be to copy the GPT UEFI files from the C: drive to a new blank Fat32 partition? (And erase the one above that I manually created in my fail attempt above?) If so, how do I copy those files, as they are scattered on the C: drive somewhere…

Solved the issue by reading more about partitions. Although I had created a new System Reserved partition on my SSD using the appropriate commends, I figured out that I needed to make the new system reserved partition “Active” and removed “Active” status from the Windows partition.

This was the key to understanding partitions:
https://www.partitionwizard.com/partitionmagic/accidentally-marked-drive-c-active.html

Reply | Quote

Great explanation, Mr. Capen!

Of course I went to disk management and found 2 GB of many Healthy Recovery and EFI Partitions:
45242-2016-08-09-13_30_43-Disk-Management.

Now 2 GB out of a terrabyte may not seem like much, but do I need all those recovery partitions? I tried to get a properties dialog, but had no luck. Is this a dangerous area to be asking about?

Thanks

Reply | Quote

Steve, that many partitions is likely to be computer manufacturer created. If you delete some of them you may have trouble booting, so I’d leave them.
If you really want to clean the disk up you should make an image backup and then re-install from scratch, using a Windows disk, not the manufacturer’s one.

Techie, you may want to re-install as well.

cheers, Paul

Reply | Quote

I am always surprised when I read an article about disk partitions and the critical design flaw in Windows is not mentioned. I find it inexcusable that Microsoft would have allowed a flaw – that adversely affects one of the most important features of its late-model operating systems, that of creation of a system image – to have crept into its design and not have been remedied long ago.

The system reserved partition is where the geniuses at Microsoft decided would be a good place to store the volume snapshot data when creating a disk image. Unfortunately, it is also where they decided to store other data as well – and that latter data grows in size over time. At some point, it grows to the point where there is no longer sufficient space on the reserve partition to hold the snapshot, and the disk image process fails with an insufficient space warning, despite the fact that there may be abundant free space remaining on the other partitions of the disk. From that point on, the disk image function is no longer available to the user, despite the fact that it is the single best way to ensure that you can get back to your current configuration in the event of a disk failure.

Back when Maxtor had its own version of this feature, SafetyDrill, I used it regularly, and it saved my bacon several times. I think I stopped using it because it didn’t support 64 bit OS’s, and around that time Microsoft began offering bundled disk image software that did. But it was a while before I discovered the above flaw that made it useless.

The workaround is so arcane – involving shrinking one partition, creating another partition, moving the boot files to it, and using DISKPART to make that partition the active one – at an elevated command prompt, no less – that it is effectively no solution at all for users to whom the command prompt is a foreign notion.

I find it an indictment of Microsoft’s design logic that they have allowed this to occur, notwithstanding widespread availability of free third party solutions not subject to such a flaw.

Reply | Quote

Thanks to all, but so far I’m not getting an answer that makes sense to me. Perhaps I didn’t ask a good question. So how about: Is there a way to look at the properties of these partitions? (Like date created). If it were possible to tell which partition had the files that would kill the boot, maybe the rest could be reclaimed?

Now, your thoughts, please.

Reply | Quote

steve, the boot information is in your Disk Manager pic. The EFI partition holds the boot information and C: holds the remaining files. The recovery partitions are likely to be from the machine manufacturer and may, or may not cause problems if removed.
To view what’s on the recovery partitions try booting from a Linux live CD and reading the information on the partitions.

cheers, Paul

Reply | Quote

gsteele531, where did you get that information? I’ve not seen snapshot info stored on a system reserved partition.

cheers, Paul

Reply | Quote

gsteele531, where did you get that information? I’ve not seen snapshot info stored on a system reserved partition.

cheers, Paul

It’s not “stored” in the sense of permanently – it’s put there while the snapshot (aka volume shadow copy) data is being created during the image backup process; it’s essentially used as working space – but it has to be big enough to serve. I’ve run into this on several machines – first when my Windows Home Server began failing to back up baselines, and subsequently when creating image backups in desperation to have an image stored somewhere. You can’t just expand the partition, because it’s the first one on the disk, and there’s another right after it.

The workaround is, as I mentioned, to go into disk manager, shrink the main partition (at the back end), create a new partition following it (I use about 400 MB to be safe) in the space freed, which I assign drive letter Z, drop down to an elevated command prompt and transfer the system files there using bcdboot (bcdboot.exe C:Windows /s Z: ), then run DISKPART, select volume Z:, type “active” to make it the active partition, and then exit DISKPART and CMD. I can then reboot, and there’s plenty of working space for the snapshot data, so I can resume image backups.

Reply | Quote