from microsoft site
The ATA Interface Limit (128 GiB / 137 GB) Barrier
48-Bit LBA Support for ATAPI Disk Drives in Windows 2000
Windows 2000 Service Pack 2 (SP2) and earlier versions of Windows 2000 do not support 48-bit Logical Block Addressing (LBA) as defined in the ATA/ATAPI 6.0 specification.
The following conditions are necessary for the correct functioning of 48-bit LBA ATAPI support:
A computer with a 48-bit LBA-compatible Basic Input/Output System (BIOS) installed.
A computer with a hard disk that has a capacity of greater than 137 gigabytes (GB).
You must enable the support in the Windows registry by adding or changing the EnableBigLba registry value to 1 in the following registry subkeyhttp://support.microsoft.com/kb/305098
To enable 48-bit LBA large-disk support in the registry:
1. Start Registry Editor (Regedt32.exe).
2. Locate and then click the following key in the registry:
3. On the Edit menu, click Add Value, and then add the following registry value:
Value name: EnableBigLba
Data type: REG_DWORD
Value data: 0x1
4. Quit Registry Editor.
Seven Major BIOS Limitations:
1. Systems with BIOS dated prior to July 1994(504 MB Limitation).
2. Systems with BIOS dated after July of 1994 (2.048 GB Limitation)..
3. 4.2 GB Limitation..
4. 8.4 GB limitation..
5. 32 GB limitation.
6. 64 GB Limitation
7. 137 GB Limitation
Edited by peter99, 25 November 2006 - 06:36 AM.