Windows 10: Can I safely remove WINRE or RECOVERY partitions?
Solution 1:
Windows 10 needs only 3 partitions:
- EFI System partition, often abbreviated as ESP, is a data storage device partition that is used in computers adhering to the UEFI specification. Accessed by the UEFI firmware when a computer is powered up, it stores UEFI applications and the files these applications need to run, including operating system kernels. It is typically a 100MB FAT32 partition, and needed for EFI boot. If you still use the old MBR boot, and you can disable UEFI completely in BIOS, you can delete it. However if Windows 10 discovers that your system can boot in UEFI mode while it is being installed it will create and use this partition.
- 16MB system reserved partition, used for unknown purpose. If you delete or move it, Windows 10 will not boot.
- Main windows partition. It is usually formatted as NTFS and holds all the files.
If you install Windows 10 on a big disk, then it will allocate more space for these partitions.
The latest (approximately after 2015-12-20) Windows installation image will create the recovery partition at the beginning of the drive, before the unmovable reserved partition, and it makes it very hard to remove it. I only succeeded by interrupting a clean Windows 10 installation, moving the ESP to the beginning of the drive using gParted and then restarting the installation. 450MB recovery partition on a small Acer Iconia Tab is a huge drain on resources, considering that I would never want to recover anything from it.
From the image, you posted, it looks like you have a huge GPT partitioned disk, and you already have five primary partitions. Just delete WINRE and RECOVERY and resize Windows and you will have plenty of space for anything.
Solution 2:
The 20GB recovery partition is from HP. It will restore your system to like the day you bought it. Meaning if you bought it two years ago, it will be two years out of date.
My personal opinion is that an OEM recovery partition is worthless. Why roll your system back several years sometimes, and keep all the bloat garbage they put on it.
If you ever need to reinstall Windows 10, you'll be much better off just making a USB installation drive with the Media Creation Tool: https://www.microsoft.com/en-us/software-download/windows10ISO
This has the added benefit that if your hard drive goes bad, you still have something you can reinstall Windows with.
Windows 10 doesn't really need these OEM recovery partitions anymore because the update process and driver management is so much better now. In addition, Microsoft has made it a much more friendly process, not even requiring product keys anymore. So, if you make your own installation USB drive, you might have to download a couple of drivers afterwards but you'll be way ahead of the outdated, bloat ridden recovery HP gave you.
I believe the media you made with HPs tool is just a copy of the recovery partition they gave you, so what I said above applies to that as well.
I wouldn't remove the WinRE partition. This is part of the Shift-Restart menu you mentioned. It may not be necessary for proper operation of the computer, but potentially useful for sure. You can read all about WinRE here: https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-recovery-environment--windows-re--technical-reference
If the WinRE partition is in the way you can delete it and you can use various methods to recreate it. First, I would recommend assigning a drive letter to it and obtaining a copy of the WinRE.wim file. You'll need it to move the recovery environment somewhere later. You can obtain a copy of this file in other ways, but it will be easier just to get it ahead of time.
You have options to recreate a recovery partition later, or probably the better alternative is to put the recovery environment back on to your C: drive. Sorry, I couldn't find clear, concise, easy instructions for you to follow. But, I found this which should get you on the right track: https://www.terabyteunlimited.com/kb/article.php?id=587
It's not a huge loss if you lose this feature, but I don't want to steer you wrong and say you'll never need it.
Solution 3:
If it's a GPT partition, then you're not limited to 4 partitions. If it's an MBR partition, you can convert it to GPT without losing your existing data, but taking a full backup is still recommended. This way you'll be able to keep your recovery partition in case you need to repair you Windows installation in the future, and unfortunately you will need it!
Try using a 3rd party application like Mini-Tool or EaseUs to convert it to GPT, they're very easy to use and reliable.