Solved How to increase size of EFI Systems Partition

My internal SSD boot drive is configured thus -

according to Disk Management; however, Partition Manager shows this


I want to increase the size of the EFI system partion to 260 MB. I can shrink the 'Windows 11 Pro' partition by 160 MB but the 'Other' partition is fixed and I can't resize it.

Macrium Reflect shows the EFI partition 96% full.



How should I proceed?

Unless you have a lot of extra operating systems your booting to on the same hardware, there isn't really any reason to expand the system partition.

You do need to expand EFI partition if you're using Dell or HP management tools which flash the BIOS. They hide working files in there, and are well known in the enterprise workspace for overflowing the default 100 MB partition.

For a consumer-based brand like ASUS or MSI, that's not really a concern.

The short answer is you need one of those 3rd-party repartitioning tools to move everything sideways.

Of course they would do something stupid like that

neemobeer said:

Unless you have a lot of extra operating systems your booting to on the same hardware, there isn't really any reason to expand the system partition.

Click to expand...

I only have MR & PM in the boot menu,

However, the latest 24H2 CU will not install ("Something went wrong . . ), the associated UUP .iso will not attempt to update that way and the individual .msu file will not run.

garlin said:

The short answer is you need one of those 3rd-party repartitioning tools to move everything sideways.

Click to expand...

As I said previously, I can get 160 MB from my 'Windows' partition using 'Partition Manager'.

Do I then just delete the 'fixed' 16 MB partition, then expand the EFI systems partition, and then reboot . . .and pray it will be recreated?

Here's a short guide on cleaning up EFI files:
Low Space on EFI (System) Partition – Clean up – GARYTOWN ConfigMgr Blog

garlin said:

Here's a short guide on cleaning up EFI files:
Low Space on EFI (System) Partition – Clean up – GARYTOWN ConfigMgr Blog

Click to expand...

I'll try this over the next few days

@IanMosley
System partitions such as EFI, MSR, Recovery are fixed and no partition manager will be able to move/resize.
In order to increase the EFI System partition, You'd have to delete them then re-create with larger size of EFI System.
1. Open Admin command prompt, type: reagentc /disable
2. Create a backup image with Macrium. Once done, boot the PC with Macrium Rescue disk
3. Once Macrium in Winpe. Open Admin Prompt and type:
diskpart
list disk -> select the disk # containing Windows, replace # on next line with disk #, type:
select disk #
list par
select par 1
del par override
select par 2
del par override
select par 3
del par
create par EFI size=260
format quick fs=FAT32
create par MSR size=16
exit
Close Admin command prompt.
4. - Back to Macrium screen, click on "Create Backup" Tab, click refresh to update the change.
- Click on restote Tab, select Backup image to restore
- select Destination disk then select the same disk
- Drag and drop the C drive only to the unallocated space (next to MSR par) -> next->fimish to rectore.
- Next click on "Fix Windows boot problems", follow the screen to create a new BCD => restart
Once rebooted. Open Admin command prompt then type: reagentc /enable

To restore Files and folders from the old EFI partition, mount the EFI System then copy to the new EFI System.

Your 16mb is probably the msr

extending the esp needs adjacent free space.

In most cases that would mean shrinking the os partition first to create the free space which has to be done from outside windows, e.g. from diskgenius boot media.

Then resize the esp to incorporate the free space. Depending on the position of the msr ( if there is one) might have to shift that.

Then if the start of the os partition has been changed use bcdboot command to fix the bcd entry before attempting to boot back into windows.

**************************************************************************************


Alternatively boot diskgenius boot media. The free version will do.

shrink the windows partition from the left by lets say 400mb

delete the esp and msr

rt click the free space and select "create esp and msr"

use bcdboot to populate the new esp

it is not difficult. Need to remember to click "Save All" at top left of diskgenius

***************************************************************************************************

Fortunately in the example below there was already about 100mb adjacent free space so it was straightforward

After creating free space




rt click it




it suggests 300mb and will create 16mb msr which is fine so click OK



click SAVE ALL



it asks if you want to format the esp immediately, say yes




then can do bcdboot from cmd prompt which is available on the diskgenius pe desktop thing

Download the free stand alone version of GPARTED - create bootable media from the iso via rufus etc and boot. Then you can move, re-size, copy, re-arrange partitions etc.

Unless you have a PC from earlier than around the year 2009 then you can install Windows 11 on any hardware via dism /Apply-Image and the bootloader via bcdboot. Plenty of posts on the forum describing the process. You don't even need secure boot or a TPM. What might fail though is if Windows starts using some of the newer CPU hardware instructions which an older one won't have -- that's where Windows will hang - and its probably only a matter of time as increasing A.I needs a lot more hardware power so using some of the newer built in CPU instructions will be used.

Cheers
jimbo

Topgundcp said:

@IanMosley
System partitions such as EFI, MSR, Recovery are fixed and no partition manager will be able to move/resize.
In order to increase the EFI System partition, You'd have to delete them then re-create with larger size of EFI System.
1. Open Admin command prompt, type: reagentc /disable
2. Create a backup image with Macrium. Once done, boot the PC with Macrium Rescue disk
3. Once Macrium in Winpe. Open Admin Prompt and type:
diskpart
list disk -> select the disk # containing Windows, replace # on next line with disk #, type:
select disk #
list par
select par 1
del par override
select par 2
del par override
select par 3
del par
create par EFI size=260
format quick fs=FAT32
create par MSR size=16
exit
Close Admin command prompt.
4. - Back to Macrium screen, click on "Create Backup" Tab, click refresh to update the change.
- Click on restote Tab, select Backup image to restore
- select Destination disk then select the same disk
- Drag and drop the C drive only to the unallocated space (next to MSR par) -> next->fimish to rectore.
- Next click on "Fix Windows boot problems", follow the screen to create a new BCD => restart
Once rebooted. Open Admin command prompt then type: reagentc /enable

To restore Files and folders from the old EFI partition, mount the EFI System then copy to the new EFI System.

Click to expand...

I fixed my issue using this method.

Thank you to everyone who offered assistance.