Is there any chance that my Windows install will fail to boot after resizing its partition?

I remember that I wanted to install Ubuntu as second system on my laptop ~4 years ago, so I used live-USB with GParted to split my hard drive. Unfortunately, after this, Windows 7 failed to load (I do not remember the error text, but it probably went in a boot loop). On the other hand, I did a similar resize several times and I only broke my Windows install once, but I do not know the reason why.

Now I need to install a second OS again but I'm afraid that I might have to reinstall windows after it.

  • I did this some years ago and it went well. I can't remember exactly, but shrinking the partition went well and booting the new linux OS worked too. I had some difficulties with my Windows partition if I remember correctly. There were some bootable repair tools that fixed this for me and no data was ever lost.
    – Chris
    Oct 5, 2014 at 15:09
  • 1
    If you're worried about "safety", then make a backup first. Oct 5, 2014 at 19:38
  • @Ƭᴇcʜιᴇ007 i worry about Windows won't start after resizing its partition. I know i won't lose my data.
    – Kirill
    Oct 5, 2014 at 21:57
  • 1
    If you aren't worried about data then I'd just backup your drivers (with Double Driver) and your product keys (Produkey or Key Finder Thing) and have a bootable USB stick with Windows on it. That way, if it all goes wrong, you can quickly reinstall Windows.
    – Richard
    Sep 12, 2016 at 17:19

5 Answers 5


You can resize the Windows partition, and it will still boot. Windows will give an error at start-up the first time, saying the disk size doesn't match its records; it will run checkdisk and update its records, and then work fine. I've done this many times.

You cannot move the Windows partition though, or it won't boot. It's worth pointing out that if you shrink from the left side of the Windows partition, what you are actually doing is shrinking, and then moving; ONLY shrink from the right side of the partition. You also should not expand the partition on the left side, as again you're actually moving it to the left, and then expanding off the end; ONLY expand from the right side of the partition.

I would also point out that partitioning is never a 100% safe activity. You are altering the partition table; if that fails (slim chance) your entire disk is at risk for data loss. It's always a good idea to have a backup of your entire drive before engaging into any form of partitioning, not that most people actually do it.


Windows can shrink its partitions, too, so why not go with that?

Simply open Disk Management, right-click on the partition you want to resize and fire away. Safety guaranteed.

If you find the space you can gain to be too small, you could defragment the partition (even if it's on a SSD). Don't expect too much, though, there are many immovable elements on a partition.

  • 4
    This rarely works in my experience, even after defragmenting the SSD with lots of free space. GParted is much faster and safe enough if you follow proper procedures. Oct 21, 2015 at 15:37
  • @ChristopherMarkieta It may appear more capable, but a reverse-engineered NTFS driver will only get you so far. Using Windows is simply the only safe option.
    – Daniel B
    Oct 21, 2015 at 17:47
  • 3
    Yeah, definitely can't expect anything from the built-in Disk Management, even after defragmenting. Booting live Linux and using Gparted or similar is basically the only way to get results, because Windows can't move the files itself while booted for whatever reason. Apr 5, 2016 at 21:19
  • The reason is if you boot from a partition, then that partition's files are in use and so should not be moved. If you want to use windows, you should use a startup usb drive or CDrom with windows on it. Same thing if you are in linux, probably: dont work on the partition that is actively running. In fact, Gparted needs an unmounted partition when it works on it, so it prevents you from moving the running OS.
    – vinnief
    Jan 25, 2022 at 17:22

You should have no issues with Gnome Partition Editor and resizing Windows partitions. I have used in countless times with no issues.


I just used GParted to reduce my Windows a further ~100GB more then Windows Partition Manager would. I carefully watched the process, and it moved over 30GBs in the process.

It worked without a hitch: it's a very smart program. I now trust it. It ended up leaving Windows with less than 1% usable space! Which is great because i could get into Windows 10 and remove over 30% of the stuff, which makes it run better. But be careful.

This fact points out that GParted awesomely moved all the files in the NTFS folder to a tight nit space, and ... I saw it smartly checking for boot loading ability, and checkdisk as well for Windows. Brilliant.

  • Gparted can't run "chkdsk", that's a Windows executable. It will indeed likely check for bootability though Mar 28, 2021 at 14:32

Resizing the boot partition with an external editor (for example GParted) doesn't appear to work for non-NT versions of Windows. Booting will cause an unspecified error on my ancient Windows 98SE virtual machine.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .