Fdisk Tutorial: Removing and Creating Partitions

Posted October 4, 2005 by Chillyb in Windows installation

This tutorial describes using FDISK to remove all data and partitions on a drive.


Warning: Using Fdisk as described here will erase all information on the hard drive.

The Basics of Fdisk:
Primary partitions are the only ones that are bootable. They are always the C: drive when active. Normally, you can only have one, but more are available with some special tricks, etc. Extended partitions are needed when you want more than one partition. You can only have one extended partition. Logical drives come into the extended partition. Since you can only have one primary and one extended partition, logical drives are useful so that you can get more than two partitions. They would be your D:, E: drives, etc.

First, you need to reboot your system with the boot disk inserted.

1. At the A: prompt, start FDISK.

2. If asked to use large-disc support, select Yes.

3. The first screen looks like the following:

Create Dos Partition or Logical Drive
Set Active Partition
Delete Partitions or Logical DOS Drives
Display Partition Information
Change current fixed drive. (in case you have two or more hard drives)
To prepare, you should have already done a backup of your data.

4. Next, we need to remove the existing partitions. Go to 3.

5. The next screen looks like the following:

Delete Primary DOS
Delete Extended DOS
Delete Logical Drives
Delete Non-DOS
Delete always in the following order

Logical (All) > Extended > Primary (Last)

6. Go back to the first screen after all partitions have been removed.

7. Now, we need to set up our new partitions. Go to 1.

The screen now looks like this:

Create Primary DOS
Create Extended DOS
Create Logical DOS Drives
Here we create in the following order

Primary > Extended > Logical Drives.

8.First, create the primary. If asked to use all space say No, and enter the amount you wish for the C: drive. It should be set automatically to be the (only) active partition. If not, it may ask you or you have to select “2. Set active partition” from the main menu.

9. Next, create the Extended Partition. Use all the space that is left.

It probably advances automatically to the next step, creating the logical DOS drives.

10. Enter the amount you wish for the D: partition and then the rest for the third partition.

Think first about the size of the partitions.

Now we are finished with FDISK, so just exit it. Next, you need to reboot with the disc still inserted and format all partitions. (The C: partition might need to be formatted with “format c: /s”. Check the Win95 tip.). After another reboot, you can go ahead and install Windows.

When your system supports booting from CD, just insert the Windows CD and reboot. The setup will start.

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