Background

The first step in getting Windows 98 to work with large hard drives is to make sure your BIOS can support the drive you want to use. Research any limitations at your motherboard manufacturers web site. All modern motherboards have a flashable BIOS that can be updated if necessary. Be sure your motherboard supports Logical Block Addressing (LBA).

Most hard drive manufacturers supply software to overcome BIOS limitations with their hard drives, such as Seagate's DiscWizard or Western Digital's Data Lifeguard products.

Microsoft Windows 98/98SE Limitations

The Windows 98/98SE 64GB barrier is not a limitation of the operating system at all. Rather, the barrier is caused by the Microsoft disk setup tools, FDISK.EXE and FORMAT.COM.

Additionally, Windows 98SE has a default limitation of 137GB for ATA interface disc drives. Theoretically, you could then partition your boot drive for 137GB, but a limitation of the Microsoft SCANDISK and DEFRAG programs reduces the practical size to 127GB.

FDISK.EXE - the Microsoft Disk Partioning Utility

The FDISK program that ships with Windows 98 has a drive size calculation problem because of some 16-bit values internally used to calculate the size of the drive. Some of these variables overflow when the drive size is equal to or larger than 64GB. FDIDSK then displays the drive size minus 64GB.

The FDISK program also has a maximum drive size limit of 512GB. Microsoft suggests that FDISK not be used to partition hard drives larger than 512GB and that a third-party program be used instead. (Partition Logic, Ranish Partition Manager and Partition Commander will work).

Microsoft has an updated version of FDISK.EXE to fix this problem.

Download the English version of the new FDISK.EXE (263044USA8.EXE) here or go to their support page for more info and other language versions:

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q263044

After updating your old FDISK program, you should have this file information:

File Date  Time Stamp  File Size  File Name  Windows Version
---------  ----------  ---------  ---------  ---------------
05/19/00   10:30AM     64,428     Fdisk.exe  Windows 98
05/18/00   08:35AM     64,460     Fdisk.exe  Windows 98 SE

FORMAT.COM - the Microsoft Disk Formatting Utility

The FORMAT program that ships with Windows 98 has a drive size calculation problem because of some 16-bit values used internally to calculate the size of the drive. Some of these variables overflow when the drive size is equal to or larger than 64GB and FORMAT displays the drive size minus 64GB.

This is a display, or cosmetic, issue only. The drive will still format to its full capacity. Microsoft has not released an updated program to correct this flaw.

SCANDISK & DEFRAG

The Windows 98SE SCANDISK and DEFRAG utilities are 16-bit programs. Because of this and limitations of the FAT32 file system, they will not function on partitions greater than 127GB. There are no fixes available from Microsoft for this limitation.

Running SCANDISK on a FAT32 partition > 127GB will cause an "Insufficient memory" error.

Although you can partiton a disk up to 137GB, it is recommended that you create partitions smaller than 127GB so that they can be managed by the native Windows 98SE ScanDisk and Defrag utilities.

For disk partitions between 64GB and 127GB in size, you must have 32KB cluster size with FAT32 formatting for SCANDISK to run.

60GB Hard Drive Checklist

[X] If your BIOS supports this size drive, no additional steps should be necessary.

80GB & 120GB Hard Drive Checklist

[ ] Download and use the updated FDISK.EXE utility program from Microsoft.
[ ] Use the Windows 98 FORMAT.COM utility program. Note that while the prgram is running it will display an incorrect size for your partition. After it has finished, the summary screen will show the correct size that was formatted.
[ ] Be sure your FAT32 partition has 32KB cluster size. A free utilitiy to format large disks as FAT32 instead of NTFS is FAT32 Formatter from Ridgecrop Consultants in the UK.

Tip: Formatting large hard drives is extremely slow. If you have a disk setup utility that came with your new hard drive, use it instead of FORMAT.COM. This can save you HOURS of waiting.

160GB & Larger Hard Drive Checklist

[ ] Download and use the updated FDISK.EXE utility program from Microsoft.
Keep your partiton size for the Primary partiton that is to be used for drive C: to 127GB or less.
[ ] Use the Windows 98 FORMAT.COM utility program. Note that while the prgram is running it will display an incorrect size for your partition. After it has finished, the summary screen will show the correct size that was formatted.
[ ] Be sure your FAT32 partition has 32KB cluster size. A free utilitiy to format large disks as FAT32 instead of NTFS is FAT32 Formatter from Ridgecrop Consultants in the UK.

Tip: Formatting large hard drives is extremely slow. If you have a disk setup utility that came with your new hard drive, use it instead of FORMAT.COM. This can save you HOURS of waiting.

(Unofficial) Windows 98SE 48-bit LBA patch

Some users are reporting success in using large hard drives by patching the Windows IDE driver to use 48-bit Logical Block Addressing (LBA). For more information, go to this site 48bitLBA.com.

Additional Referrences

Microsoft Knowledge Base Article - 263044
Fdisk Does Not Recognize Full Size of Hard Disks Larger than 64GB
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q263044

Microsoft Knowledge Base Article - 263045
Format Displays Size of Partitions or Logical Drives Larger Than 6 4GB Incorrectly
http://support.microsoft.com/default.aspx?scid=kb;EN-US;263045

Microsoft Knowledge Base Article - 184006
Limitations of FAT32 File System
http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q184006&