Author Topic: Using FDisk to Partition  (Read 1230 times)

Offline scuzzy

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Using FDisk to Partition
« on: Aug 16, 2002, 04:30 PM »
Note: I wrote this long before Windows XP was made available to the public. In my example, I used 3GB for the operating system, which is anemic for Windows XP. I recommend at least 8GB for Windows XP, although 10GB is more realistic. Windows XP also has its own partitioning and formatting utility, which is available during a clean installation. - Scuzzy

Before even thinking about using FDISK, you must clearly understand that after using it, you MUST reformat your hard drive, PERIOD. So, be prepared. Here's the warning: If you don't want to reformat your hard drive, then DON'T use FDISK. Now, it only makes sense that if you're going to use FDISK you should have a good backup of what's important to you. Also, make sure you have a high quality, formatted system floppy disk with at least the following files: FDISK.EXE, SCANDISK.EXE, ATTRIB.EXE, LABEL.EXE, MSCDEX.EXE, FORMAT.COM, EDIT.COM, and your CD-ROM drivers. (I keep a second floppy as emergency backup.)

Also, before using FDISK you should have a good idea of what you'd like your hard drive to look like. Do you want 3 partitions? 4? 5? Why? What size do you want the partitions (or drives) to be? How will you use them? Answering these questions ahead of time will save you grief later. Keep in mind that the smaller the partitions, the easier it will be to keep everything in its place. But, too many partitions can also be difficult to manage. Plus, you want to make sure each drive you create will be large enough to support its intended purpose, along with future expansion. If you have a 4.3 GB hard drive, for example, you probably won't want to make 5 drives out of it. You may want just 2, maybe 3 at most. If you have a 10 GB hard drive, though, you may want 3 or 4 drives. If you plan to use a scanner, it's a good idea to create a large C drive partition. Scanners can create VERY large temporary files on the C drive (easily over 500MB) when scanning on high resolution.

From here on, because of the way FDISK works, we need to refer to the size of your hard drive and partitions in megabytes. For example, if you have a 20 GB hard drive, let's call it a 20,000 MB hard drive (sort of, since one megabyte is actually 1,048,576 bytes. So, more accurately a 20 GB hard drive is about 19,073 megabytes.) Since I have about a 19,073 megabyte hard drive, let's look at the way I decided to break mine down:

Drive C: 3,000MB (Operating System)
Drive D: 4,300 MB (Programs)
Drive E: 4,300 MB (Programs)
Drive F: 4,300 MB (Programs)
Drive G: 3,170 MB (Files & Downloads)

By the way, don't worry about how the numbers add up, since FDISK will round the numbers.

Next, we need to understand how FDISK works. Despite popular belief, FDISK creates 2 DOS partitions, regardless of how many drives you create. DOS Partition 1 automatically becomes the PRIMARY DOS Partition, and also the C drive. DOS Partition 2 automatically becomes the EXTENDED DOS Partition, which holds the "Logical" drives (D, E, F, etc.). If you decide that you only want one single large drive, then DOS Partition 1 will be 100% of the hard drive, and DOS Partition 2 will be 0% of the hard drive.

Now, let's confuse you a little bit. What if you have 2 physical hard drives? Here's how it works: The MASTER hard drive (Drive 1) is assigned drive C for its Primary DOS partition, and the SLAVE drive (Drive 2) will be assigned whatever drive letter follows the last one that was assigned to the master hard drive. For example, if the master hard drive is partitioned to C, D & E drives, then the slave drive will begin with F drive. The logical drives for the slave will continue with G drive, H drive, etc. However, in order for it to work this way, you must assigned C drive (on the master hard drive) as the "active" partition, and you must ensure that no drives on the slave are set as active. More on that later.

Okay, in my example my physical hard drive holds about 19,073 MB. Drive C is my active Primary DOS partition and is 3,000 MB in size. That leaves somewhere around 16,073 MB for my Extended DOS partition which holds Logical drives D, E, F & G for which the sizes are as listed above.

Now that you have an idea of how FDISK works, let's go into actually using it.

Using FDISK:

If you've made it this far, then you are probably prepared to actually use FDISK. So let me say this: don't be afraid of it. As a matter of fact, play around with it until you get used to it, as it is a little odd. The only reason I can think of that you might have any fear of FDISK is that you are not prepared to reformat your hard drive.

  • From the DOS prompt, type FDISK and press enter.


If you have Windows 95 SR2 or Windows 98, you will have the option of enabling large disk support, or FAT32. (It isn't true that once you select FAT32 you can never go back to FAT16. In fact, you can. All you have to do is run FDISK again.) You will get a message something like:

Do you wish to enable large disk support (Y/N) [N]

To enable FAT32, type Y and press enter. To keep FAT16, type N and press enter. (Any drive 512 MB or smaller will automatically be FAT16 regardless of what you selected.)

NOTE: FAT16 is the original FAT (File Allocation Table) before FAT32 was introduced. FAT32 will support hard drives and partitions up to 2TB (Terabyte) in size, FAT16 will only support hard drives and partitions up to 2GB. Due to FAT16 limitations, a single-partition 40GB hard drive would only be good for 2GB. FAT32 also uses clusters more efficiently. For example, on drives up to 8GB, cluster sizes were reduced from 32k (FAT16) to 4k(FAT32). This makes better use of available hard drive space.

Next, you will be in the FDISK Options screen, which gives you the following to choose from:

1. Create DOS partition or Logical DOS Drive
2. Set active partition
3. Delete partition or Logical DOS Drive
4. Display partition information
5. Change current fixed disk drive (use this option to switch between hard drives)

To create the new and improved partitions, first delete the current setup in the following order:

a. Delete the Logical drives, working backwards, one at a time.
b. Delete the Extended DOS partition.
c. Delete the Primary DOS partition.

The concept is simple: You cannot delete the Primary DOS partition until the Extended DOS partition has been deleted and you cannot delete the Extended DOS partition until the Logical drives have been deleted.

NOTE: If you currently only have a C drive, you will only need to delete the Primary DOS partition.

  • From the FDISK Options screen, select 3 to Delete partition or Logical DOS Drive. This will take you to the Delete DOS Partition or Logical DOS drive screen.
  • Next, select 3 to Delete Logical DOS drives.
  • Follow the instructions to delete each Logical drive, one at a time, working backwards.


NOTE: Each time you go to delete a drive, FDISK will prompt you to enter the volume label of the drive to be deleted. (FDISK provides the volume label for each drive under the headings.) However, some drives may not have a volume label. In that case, simply leave that field blank and press enter.

Now, you are ready to delete the Extended DOS partition, followed by the Primary DOS partition.

  • From the Delete DOS Partition or Logical DOS drive screen, select 2 to delete Extended DOS partition.
  • Finally, select 1 to Delete Primary DOS partition.


Once you've deleted the above DOS partitions, you will be ready to create the new DOS partitions.

Creating the new partitions:

At this point, we'll work opposite from the way we deleted the partitions. First, we create the Primary DOS partition, then the Extended DOS partition, then the Logical drives.

Press escape to return to the FDISK Options screen.

  • Select 1 to Create DOS partition or Logical DOS Drive and press Enter.
  • Select 1 to Create Primary DOS Partition and press Enter.
  • When prompted if you want to use the maximum available size, select NO.
  • You'll then be prompted for the size you want the partition to be. Be aware that FDISK may default your entry to a rounded number.
  • Press escape to return to the previous screen, then select 2 to Create Extended DOS partition.
  • Accept the default number provided by pressing enter. This time, you WANT the maximum available size for the Extended DOS partition.
  • At this point you will begin to select the size of each Logical drive. You can create Logical drives until you run out of hard disk space.


If at any point you are not satisfied with your new partitions, you will have to go through the process of deleting what you created, and recreating the new partitions and Logical drives. You cannot simply have FDISK re-size your partitions. Unfortunately, it doesn't work that way.

Once you're happy with the partitions you've setup, select option "2. Set active partition" from the main FDISK menu, and ensure C drive is set as the active partition. If you're using FDISK on a slave hard drive, make sure that no partition on the slave unit is set as active. FDISK, by default, should not allow you to set a partition on the slave drive as active.

That's it. You'll now want to close out FDISK, restart your computer with your system disk in the A drive, and format each individual drive you created. Finally, install your Operating System.
« Last Edit: Jan 15, 2004, 07:37 AM by Scuzzy »
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