Distros : Prep - GParted
GParted is a brilliant
tool to graphically manage your disk partitions. You can resize, copy, and move partitions without data loss.
It is available as its own live boot disk that has a minimal Desktop with a super quick Web Browser, a File Manager and various Command Line Utilities.
There are two ways to partition a Hard Drive..
- MBR - Master Boot Record, the old way that worked with BIOS.
- GPT - GUID Partition Table, the new way that works with UEFI and modern hard drives.
Disk with MBR Partitioning Scheme
Booting into Puppy Linux I ran GParted to examine the Hard Drive on a old Dell Inspiron Laptop that originally ran Windows Vista.

Linux sees the hard drive as /dev/sda, it has a total size of 55.89GiB,tiny by today's standards, which is split up into three Primary Partitions.
- /dev/sda1 - DellUtility which you can boot into to troubleshoot hardware issues.
- /dev/sda2 a Recovery Partition that can be used to reinstall Windows Vista.
- /dev/sda3 the Main Partition that Windows uses as
C:\
.
/dev/sda4 is an Extended Partition with one Logical Partition /dev/sda5 which is 2GB in size. Whatever its purpose was is now history as Vista has long since become defunct.
MBR Hard Drives can only have Four Primary Partitions but a work around was developed that changed one of the Primary Partitions into an Extended Partition which then could contain a number of Logical Partitions..

To make disk space available for a Linux installation I am going to delete all the partitions on this hard drive bar /dev/sda1 the DellUtility one.
Before you delete a partition always check to make sure that there is no valuable data on it, use puppy to mount that partition and browse the file system and copy important files to a USB Key or start Puppies Samba Server and copy the entire Windows User Directory or entire partition over the network to a PC with a large enough hard drive.Take your time because when the data is gone, it's gone, unless you have a pile of money to pay to have it restored!!!
Deleting Partitions is so easy, just Right Click it and choose Delete. With an Extended Partition you have to delete all the logical partitions first.

GParted lists out the pending operations, nothing has happened yet, I can cancel them, no time to NUKE Vista, I click Apply, the deed is done.
Now to create my first partition, most Linux Distro use a Swap Partition (Windows uses a Swap File), if the Operating System runs out of system memory RAM it can free up some by moving less used data in RAM over to the Swap Partition, it can then take that data back when needed.
This Laptop has only 1GB of RAM, one suggestion is to create a swap partition twice the size of RAM, so mine will be 2 x 1GB = 2GB.

Sizes are quoted in MB as 1GB = 1024 MB
my partition size is 2048 MB. Its going to be a Primary Partition and it will be formatted as linux-swap.
The third and final primary partition will use up the rest of the Hard Drive.

I left the new size as is, again its going to be a Primary Partition and this time I choose to format the partition as ext4 File System.
There are many file systems for Linux and the type you use will depend on the size of the partition and the features you require, check here for a summary on linuxiac.com.
I find it easier to Partition and Format the Hard Drive first before I boot into a Linux Installation ISO especially if I want to install Linux beside a Windows OS.

The Operations are queued up, waiting for me to click Apply.
- DellUtility will remain as /dev/sda1
- The Swap Primary Partition will become /dev/sda2
- The remaining Disk will become Primary Partition /dev/sda3
Now to download a Linux ISO, as this is an old 32bit Laptop I am going to install the 32bit version of Debian 11..
Disk with GPT Partitioning Scheme
Fast forward to err 2014 and I boot up a Fujitsu LifeBook A512 laptop that originally ran Windows 7, now Windows 10 and use its Disk Manager to view its setup..
In the search box type in hard drive
and you will get a link to Windows Disk Manager or Right Click the Start button and find a link there or else Windows Key + R for run and type in the command diskmngr.msc

You can tell that it has a GPT Partitioning Scheme Disk because of the existence of an EFI system partition. The Hard Drive is 465.64GB in size with the Windows Partition taking up most of. I want to shrink this partition and delete the 15GB recovery partition to make room for Linux, but first some housework..
While in Windows I used Explorer to tidy up files, delete what I definitely no longer needed and although it isn't necessary I ran the Disk Defragmenter to place all the files nice and consistent (contiguous) to the left leaving clear space on the right which may speed up the resize process and may help to recover from if anything stops that process midway.
In the search box type in defrag
and you will get a link to Defragment and Optimise Drives select the drive and click on Optimize.

This process can take some time so put the kettle on!!!
Finally the defrag is finished, its time to reboot back into puppy and make this PC Linux friendly.
Using GParted to get a better overview of the hard drive and yes it is a GPT Disk and the Windows partition (C: Drive) is actually the forth partition /dev/sda4.

The first partition /dev/sda1 is a 1GB Diagnostic Partition, that you can choose to boot into rather than Windows to do some basic tests on the pc.
The second /dev/sda2 is the EFI partition the new BIOS.
The third /dev/sda3 is a Microsoft Reserved Partition MSR that Windows uses to deal with GPT Disks. Microsoft's Disk Manager does not display this partition.
The fifth /dev/sda5 is a Recovery Partition giving you an option to reinstall Windows.
If you care about Windows you should read this first, I don't, so I right clicked the Recovery Partition /dev/sda5 and choose Delete and clicked Apply to perform the action.
Easy PC, but before I shrink that Windows Partition /dev/sda4, yet more housework, I backed up the contents of the Users folder by mounting that partition and used Samba to share it over the Network to a PC with a decent sized hard drive.
To resize a partition click on it and click on Resize/Move and either drag the green box to the new size or enter it into the New size: box.

I intended to have 104GiB of free space after the operation, so my calculation for the new size should have been 352901MiB
448.63 - 104 = 344.63GiB and to convert that to MiB's X 1024 = 352901MiB
however my maths went slightly astray :-(
I clicked on Apply to start the process, then I thought that it would of been better to use the latest 64bit version of GParted rather than the 32bit version but it was TOO LATE to change my mind.

GParted uses various ntfsresize commands...
ntfsresize --force --force -s 386311127040 --no-action '/dev/sda4'
And will take a looooong time, only two hours remaining!!

Finally the operation is successful taking nearly three hours to complete!!!

I booted back into Windows 10 to check that all is OK, Windows Disk Manager sees the different size of the Windows partition and the almost 104GiB of unallocated space.

Back to puppy and GParted to prepare the hard drive for a Linux Install. I queue up two operations to create a 4GiB swap partition and a partition to use the rest of the disk formatted as Extended 4.

I clicked Apply and the hard drive is ready for the latest 64bit version of Debian!!