Q4OS Forum

CattyFae

Member

Registered: 2026-01-31

Posts: 1

how to resize the root disk for Q4OS if you used windows installer

First, make a backup of your files in your Q4OS installation before you proceed, I recommend using Pika Backup

Next, reboot into windows
(and make sure you have enough free space on C: for the increased volume size in linux)

In the start menu, find Notepad, run this as an admin

In notepad go to the File menu, select Open, and browse to

c:\Linux64\Debian12_s001\install\

(the name may vary for your install, make sure you use the path that leads to your version of Debian)

find the file called "preseed.cfg"

find this line:

d-i wubiapp/disksize1 string xxx

xxx=will be the current size of the volume in megabytes
(so make sure that you calculate the correct size in mb that you want your disk to be and type in the correct number)

for this example, we'll change it to 500GB
edit the line to:

d-i wubiapp/disksize1 string 512000

save the file, close notepad.

In the Start menu, search for cmd, run this as an admin
in the cmd window run these commands

cd\

cd Linux64\Debian12_s001\disks\

fsutil file seteof root.disk 536870912000

(again, the number here is 500GB)

Once that command completes, close the cmd window

Lastly Use windows explorer to browse to

c:\linux64\debian12_s001\install\

and delete stp_disk1expanded.stp

then reboot into Q4OS the filesystem will resize during reboot.

it will take longer for your PC to load Q4OS after you reboot from Windows- that's normal, everything should work fine with more storage space

Last edited by CattyFae (2026-01-31 23:13)

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Best Regards, Cres (they/fae)