Never Re-install Windows Again Part 2: Partitioning your hard drive

Warning: Drive partitioning is an inherently risky process. If something goes wrong you may lose all your data and you PC may become unbootable. Do not attempt any of the following procedures unless your data is full backed up and you have a Windows installation disk available. If you have any doubts about your technical ability to successfully carry out these procedures then don't; the risk is too great.

In this article I'll show you how to partition (or divide) your current C: drive into two smaller drives (partitions) so that the first partition C: will contain your Windows operating system (and some of your data) while the second partition will contain just data. 
The process involves creating a second partition using the free space on your C: drive then, after the partition is created, moving some of your data from the C: drive to the new partition.

Step 1: Determine your free disk space

The first thing you need to do is determine whether you have enough free disk to allow partitioning. If you don't, you can't partition your drive without first moving some of your data off your C: drive to an external USB drive, CD/DVD or online backup service..
Go to My Computer and note the size of your C: drive and the amount of free space available. In the following example the C: drive is 186 GB drive and has 169 GB of free space. The difference between them is 17GB; that' s the amount of space currently being used.
What this means is that I can create a large partition of up to 169 GB using the free space and have plenty of room on the second partition to move my data from the first partition.
If your drive is like this and has more free space than space used then you don't have a problem. You can go straight to Step 2 below.
But what if you don't have that much free space?. For example what if you had 100 GB used and only 86 GB of free space? On the face of it it may appear that there's not enough room but in fact it's still possible.
That's because you don't need  to move all the 100 GB that's currently on the C: drive onto the second partition.
Let's work out how much data you actually need to move. More specifically we are going to work out what you not going to move and subtract that from the total amount of data on your C: drive. The difference is the amount of data you are going to move.
From My Computer double click on the C: drive. You should now see all the folders on the C: drive.
Now right click on the Windows folder and select Properties. The folder size will then be calculated. Write down the final calculated figure for "Size on disk."
Do the same for the "Documents and Settings" and the "Program files" folders and then add the total disk space taken by these three folders. For example let's us say you came up with these figures:

Windows4.2 GB
Documents and Settings7.6 GB
Program Files4.7 GB
Total ("system space")16.6 GB

Let's call the total the "system space."  Your system space could be anywhere from 4GB to 20GB depending on the number of programs on your PC and the amount of data you have accumulated.
We won't be moving any of the files in the system space to our new partition so we don't need to allow for that space on that new partition.
So subtract the system space from the disk space used on the C: drive. The difference is the amount of data you have to move to the new partition.
Here's the calculation for our example using a 186 GB drive with 100 GB used and 86 GB of free space:
Data to be moved = 100 GB - 16.5 GB = 83.5 GB
So we have to move 83.5 GB to move. As we have 86 GB of free space that's enough. That's means we can create a 86 GB partition and have enough room on that partition to move onto it all our data we need to move..
If when you do the calculation for your PC you get a similar result, i.e. plenty of room, then you can stop reading now and move on to step 2.
If you still don't have enough spare disk space then I'm afraid you will have to backup some of your data onto a USB hard drive, flash drive CD / DVD or online backup service and then delete it from your hard drive.
The amount of data you need to backup and delete can easily be calculated by the formula:
Data to be backed up and deleted from C: = (total drive space used - drive free space - system space) divided by 2.
So if our 186GB drive has 150GB used and only 36GB free the amount of data to be backed up and then deleted from C: would be:
(150-36-16.5)/2 or 48.75GB.
That's quite a lot of data to backup and deleted but I'm afraid that's what's necessary if you want to partition your drive. Don't move on to step 2 until you have freed up this disk space.
Step 2: Download the partitioning software and burn it to a CD
Download the software: The freeware product we will be using is the GParted Live CD. Download the 51.2MB file called gparted-livecd-0.3.4-10.iso from here.
Burn the ISO file  You must burn the ISO file you downloaded to a CD. Most CD burners will allow ISO burning but if yours doesn't then you can find a freeware ISO burner here along with instructions how to use it.
Test your newly burnt CD by putting it in your CD drive and rebooting. Your PC should boot from the CD and bring up the Gnome Partition Editor boot options screen (see screenshot below). If your GParted CD boots fine then remove the CD from the tray and boot back into Windows. You can now go to Step 3. 
If your CD doesn't boot then the most likely problem is that you didn't burn the ISO correctly so try again. A common mistake is to copy the ISO file to the CD rather than burn the image to the CD. Read your burner instructions for help.
It's also possible you BIOS is not set properly for CD booting. If so, you may find this guide useful.
Step 3: Prepare your hard drive for partitioning
Check your C drive for errors: From Windows go to My Computer, right click on your C: drive and select Properties / Tools / Error checking / Check now  and then check both boxes and press Start. Windows will ask if you want to schedule the disk check next time you restart Windows. Answer "Yes" and reboot. The disk check could take some time; anything from 5 minutes to two hours depending on your drive size and the number of files on the drive.
Defragment your disk: After the disk check has completed Windows should reboot. From Windows you should now defragment your drive. You can use the defragmentation program built into Windows but you'll get better results using a third party defragger. For this application I recommend JKDefrag which you can download for free from here .
JKDefrag does not require installation; it can be run directly from the .exe file. In fact that's all you have to do. Just double click the .exe file and the defragmentation will start.
Defragmentation may take anything from a few minutes to a few hours depending on the size of your hard drive, the number of files on it and the degree of fragmentation. JKDefrag shows you its progress so you can decide yourself whether you should hang around or take the dog for a walk.
Step 4: Partition your drive
We are now ready for partitioning. In this step I'll show you how to:
    • Start the GParted partitioning program
    • Reduce the size of your C: partition
    • Use the spare disk space to create an extended partition
    • Create a logical drive for your data within the extended partition
Start the GParted partitioning program:
Put the GParted CD you created in step 2 in your PC's CD tray and reboot. Once the PC boots from the CD you should get a screen that looks like this: (apologies for the quality - I had to use a digital camera)

Press <Enter> to accept the default "auto-configuration" boot option. As the boot proceeds press <Enter> when asked; once to accept the default keyboard and again for the default language.
Finally when the boot has completed GParted should come up the desktop. It will look something like this. 
This display for my test PC shows a single line for a hard drive called "hda1" of 186.3 GB capacity with 17.28GB used. Your figures will of course be different. 
The name "hda1" is the Linux way of referring to your hard drive. It's roughly equivalent to  "C:" in Windows.
If more than one line appears on this display and you know you have only one physical hard disk in your PC then your drive is already partitioned and you should abandon any attempt at further partitioning. That's for experts only.
Computer hardware vendors like Dell quite often put "hidden partitions" on the the disks of the computers they sell. They do this for support reasons: a customer's computer can be restored to its original state from the hidden partition.
These hidden partitions may be "hidden" from Windows but they will show up in GParted. So don't be surprised if you find one of these partitions, they are common. If you do, it's time to bail out as adding further partitions or deleting the hidden partition may have unknown consequences.
Reduce the size of your C: partition:
Right click on the disk drive (that's the line starting with /dev/hda1) and select "Resize/Move" from the menu.
Enter in the "New Size" box the desired size of your system partition in megabytes. This figure should be the used space plus an allowance of 1000-2000MB rounded up to the nearest 1000. The extra space is to allow for the possibility your paging file may grow and other general contingencies.  If your space is really tight just round up to the nearest 1000
So in the example from Step 1 above, our used space was 17000MB (17GB). Lets take this up to 20000MB (20GB) . To do this we would enter 20000 in the "New Size" box.
After entering the size of the system partition click in the box below labeled "Free Space Following."  GParted will then calculate the free space for you.  Your screen should look like the one below though obviously the figures will be different..
 Now click the Resize/Move button. You should see something similar to this:
Use the spare disk space to create an extended partition:  Right click on the "Unallocated" bar and select "New."  From the pull down menu next to "Create as" select "Extended Partition." Your screen should look like the one below. 
 Now press the Add button. You should now see something like this:
Create a logical drive for your data within the extended partition:  Right click on the "unallocated" bar and select "New."  Check that the number in the "New Size" box is the same as the "Maximum Size" shown at the top of the screen. If not change the maximum size.  From the pull down menu next to "Create as" select "Logical Partition." From the pull down menu next to "Filesystem" select "ntfs." You screen should look like the one below. 
 Now press the Add button. You screen should now look like this:
We are now ready to put our changes into effect.  If you feel something is not quite right then now is the time to bail out as no changes have been made to your disk. You can safely exit GParted, remove the CD from the tray and reboot Windows.
If you are happy things are as they should be then select "Edit" from the top menu bar and then "Apply All Operations." You will be asked then asked to confirm the request. If you are happy that you have your data securely backed up select "Apply"
GParted will now shrink your system partition and create your data partition. The process will take a few minutes so be patient. Once completed select "Close."  GParted will then rescan your disks. When completed select "GParted  / Quit." and your system will now reboot into Windows. Remember to remove the GParted CD from your CD tray!
Rebooting Windows may take a long time as Windows will insist on doing a thorough disk check of your new partitions. This is a good thing so please don't abort the disk check due to impatience. 
After rebooting Windows go to My Computer. You now should see two hard disk drives. One will be your reduced-size C: drive and the other be your new data partition.  The letter assigned to the new drive will depend on what CD drives and other devices you have installed. Here's how my test PC looked after partitioning.
Compare this to the first screen shot at the top of this page.
The C: disk has been reduced from 186GB to 19.5GB with 2.25GB of free space. The F: disk is the new partition. It's 166 GB in size and has all of that available as free space. That's because there is nothing on it!
Not for long. We are now going to move some of your data from the C: drive to the new partition.
Step 5: Move some of your data to the new hard drive
Ideally you should move all your user data from the C: drive to your new data partition. However with Windows it's extremely difficult to cleanly separate all your data from the operating system.
Rather than adopt a purist approach I recommend a practical one: I suggest you only move data that's easy to move and won't cause any few subsequent operational problems.
The three categories of data I suggest you move are the My Documents folder, any stand-alone data folders and your email files.
Moving the My Documents folder.  This is not complicated but you have to make sure you get the drive letter assigned to your new partition correct. In the screen shot shown above the new drive letter was F but on your system it could be something different. I'm going to use F in the following instructions but you should substitute the correct letter for your system.
What we are going to do is relocate My Documents to the folder F:/My Documents. Here's how to do it:
Go to My Documents and select Properties.
When you've clicked on Properties, select "Move" and then navigate to your new partition. That's F in my case. Then click "Make New Folder." Enter "My Documents" as the folder name and hit Enter and then OK. Windows will then ask you whether you want to move your documents; click Yes.
Moving your documents make take some time. Once moved, though, you can access them normally from the "My Documents" icon on the desktop or elsewhere.
In the process you'll free up a lot of room on your C: drive. Defrag the drive so it can be utilized by Windows in the most effective manner.
For more information you can consult this Microsoft document. http://support.microsoft.com/?id=310147
Moving Stand-alone Data Folders  Most users have created folders on their C: drive for storing MP3 files, videos, digital photos and other files. There is no reason these files can't be moved to your new partition.
Go through each of the folders on your C: drive and decide which can be moved. Folders containing installed programs should not be moved only folders containing data. If in doubt, don't move it.
When you move your data folders you may have to change the settings in some of your programs. For example if you move a media library you'll need to change your media player settings to let it know where your library is now located.
Moving files from C: to your new drive is easy. From My Computer click in the C: drive then right folder on the folder you want to move and select "Cut." Then from My Computer click on your new drive, then in a blank space right click and select "Paste."
If you are moving large quantities of data you may want to consider installing the freeware program YCopythat allows you copy without being in attendance to answer Windows copy dialog questions.
Moving Your Email Files.  This is an optional step as it'snot quite as simple as moving the My Documents folder or your data folders. The reason I suggest it at all is because email files are extremely valuable to most users and they change often. If you ever have to restore Windows you would probably not want to write over your email files with an older version. Moving your email to another partition prevents your email data being over-written.
However you can achieve a similar result by regularly backing up your email. If you then have to restore Windows you will lose your most recent email but will still have the capacity to recover that email from the backup copy.
My suggestion is that if it's easy to move your email to another partition then do so. Otherwise skip this step and put in a backup plan for your email instead. 
Some email programs are easier to move than others. That's because they store their email files in different ways and in different locations. As a result I can't give general instructions for moving your email files. Instead I'll give you some links to guides that show you how to move the email files for the most common email clients. If your email client is not shown then do a Google search or speak with your vendor.
If you can't understand the instructions in the following guides then simply don't move your email files. It's not the end of the world if they stay on the C: drive. Do however, back them up regularly.