Installing another hard disk under Windows

by Marion Bates <mbates at>

This document describes the non-obvious steps required to install additional hard disks on a PC running Windows. This has been tested with standard IDE/EIDE hard drives and Windows 98.

  1. Guess the jumper settings for the new drive. Drop jumpers on floor, spend 20 minutes crawling on hands and knees looking for them.

    Each IDE bus (typically there are 2) can have a master and slave device on it. If there is only one device on the bus, it's probably set to master, so you want to set the new drive to slave. Or maybe "auto" and let the BIOS pick it up -- hard to say, use trial and error. Connect the drive and start up.

  2. Enter BIOS setup and tell it explicitly that there is a new hard drive on the ide bus. Hopefully BIOS will detect the drive geometry/size, if not, run away. Save and exit and continue booting.

  3. From Windows DOS prompt, run fdisk (C:\WINDOWS\COMMAND\FDISK.EXE) and go to the next step. If it crashes, or if it doesn't see the second drive, boot off a Linux cd and run Linux fdisk and remove any/all partitions on the new disk, then boot back into Windows and try DOS fdisk again.

  4. You should see a message from fdisk like "Your computer has a disk larger than 512 MB", and asking if you wish to enable large disk support. ("Large disk support" means "FAT32" if that helps. Basically anything since Windows95 is FAT32-happy.) Answer Y to enable large disk support.

  5. You will see the main FDISK Options menu, and the "Enter choice:" prompt. It will tell you "Current fixed disk drive: 1" -- your startup disk. But you've just plugged in another drive and that's the one you want to f, so hit 5, then find the number next to your new drive, type it into Enter Fixed Disk Drive Number, and hit Enter. (In most cases, if you just added a second hard drive, the number from the list will equal 2. Before you proceed, double-check that the current fixed hard drive is equal to the new hard drive you just installed. If it is, you should see any number other than 1 next to Current Fixed Drive.)

  6. From the main fdisk menu, select "1" to "Create DOS Partition or Logical DOS Drive" and hit Enter.

  7. Select "1" to "Create Primary DOS Partition" and hit Enter. Your computer will verify the new drive's integrity.

  8. The next screen to appear will ask, "Do you wish to use the maximum available size for a Primary DOS partition?" Press Y if you only want to create one partition or N if you'd like to create multiple partitions on the drive. Then hit Enter.

  9. Exit fdisk, restart as it tells you. After the machine boots, double-click the My Computer icon. You should see an additional drive with the letter D: and a possible third with the letter E: (if you created multiple partitions, or if you already had additional partitions/drives to begin with.) Right-click your new D: drive and select Format from the list, and change the Format Type to Full and press Start.

  10. After formatting is complete, the new drive should then appear under My Computer, as just another drive letter. But you might have to reboot one more time.

NOTES: DOS fdisk terminology review (thanks to Vince):