0
To assume you have enough space of the win 8.1 install:
1) boot into (or use a install cd) for windows and shrink its partition to the desired extension size then boot into a mint install cd/usb
(DO NOT ATTEMPT FROM INSTALLED MINT)
2) mount and "chroot" the mint install (which has both fdisk / gparted -- for newer users gparted is hands down safer option --its also gui based.
3) then extend the 15Gb mint install by the newly re-un-allocated space and click apply.
4) then from mint installer -- open a terminal (Clt-Alt-F2 by default) and run:
sudo update-initramfs -u -k all && sudo update-grub
(FOR THIS ENSURE YOU ARE IN THE "CHROOT" --change(d) root) -- can confirm by running lsblk (which should NOT show /mnt/...... only native /, /home,etc etc.
5) exit the "chroot" via Clt_d or typing exit TWICE)
6) reboot --removing install media prior to restart
7) enjoy newly enlarged mint install on your dual booted system.
To shrink a partition should I use an install disk or can I just shrink it with Windows installed on my pc? – CrossBones – 2015-04-22T11:01:46.860
To take some space from your Windows partition, you should be able to do that inside Windows. You can use Disk Management for this. – Samir – 2015-04-22T11:22:02.640
@sammyg -- possible sure BUT you seem to be missing the data loss avoidance that method is not likely to not muck things up (use another system aka live/install media and mess with the UN MOUNTED partitions – linuxdev2013 – 2015-04-22T12:30:08.073
Do you have any unallocated space left now on the disk? – Samir – 2015-04-22T10:40:58.380
>
Which one is Windows on? The sda1? You have 18 GB on sda6. Can you take some of that? – Samir – 2015-04-22T10:46:29.620
1Is it OK if I post your screenshot here on SU? – Samir – 2015-04-22T10:47:32.210
On a second thought, this is better tutorial on commands that you will need in step 5 (look at my previous comment): http://litwol.com/content/fdisk-resizegrow-physical-partition-without-losing-data-linodecom
– mnmnc – 2015-04-22T10:49:29.780Why would he need a Live system when he appears to be able to boot into Mint Linux? – Samir – 2015-04-22T10:52:08.693
Windows 8.1 is on sda1 @sammyg – CrossBones – 2015-04-22T10:54:24.457
cant I just use gparted preinstalled in linuxmint? @mnmnc – CrossBones – 2015-04-22T10:54:28.833
@sammyg -- attempting to manipulate partitions in this way from a running install is ill-advised if not impossible givent the partition layout shown. – linuxdev2013 – 2015-04-22T10:54:43.343
@suriya, as I mentioned to sammyg since Windows is ACTIVELY using all the other partitions that is NOT possible indeed a live installer/media is the only way without possible data loss (UNLESS you have sufficient space on a spare HDD to house a backup of one or both systems then you could more sanely (properly / organizedly) partition the drive and restore the data to the respective partitions... IF you go that route I HIGHLY recommend using a gpt table not mbr (much more flexible). – linuxdev2013 – 2015-04-22T11:06:29.367
I'm afraid a GPT partition table may be impossible to boot up Windows from. I believe it requires that the system is UEFI based, or EFI based at least. It won't work with BIOS based systems. I believe Linux will, but not Windows. – Samir – 2015-04-22T11:17:57.630
1Since data preservation is one of the objectives here, I would strongly recommend that you backup any important files to an external disk. – Samir – 2015-04-22T11:23:46.970
@sammyg AS long as bios is set to CSM (legacy mode) GPT is wind/linux/(even older pre2009 mac) friendly – linuxdev2013 – 2015-04-22T19:14:37.473