Check this lik from Maxtor:
The full capacity of ATA drives larger than 137GB is not recognized by the operating system.
Currently, there are three options to remedy the 137 Gigabyte barrier. Failure to implement one of the following installation options will result in data loss when trying to access the hard disk beyond 137 Gigabytes.
Installation Option 1. Upgrade the operating system to either Windows 2000 with Service Pack 3 (or newer) or Windows XP with Service Pack 1 (or newer) and download the Maxtor Big Drive Enabler software patch. The Maxtor Big Drive Enabler, once executed, will update the Windows registry for large drive support.
Installation Option 2. Download and install the Intel Application accelerator. The Intel Application Accelerator provides 48-Bit LBA compliant ATA/ATAPI controller drivers (IntelATA.mpd) and replaces the Windows 98/Me, 2000 and XP ATA controller drivers (ESDI_506.PDR). Intel is the only chipset manufacturer that we are aware of that offers a compatible controller driver for Windows .
The Intel Application Accelerator only supports the following chipsets: 810, 810E, 810E2, 810L, 815, 815EP, 815G, 815EG, 815P, 820, 820E, 840, 845, 845E, 845G, 845GE, 845GL, 845GV, 845PE, 850, 850E, 860. The Intel Application Accelerator can be obtained at http://www.intel.com/support/chipsets/iaa/.
If you have an unsupported chipset or do not want to upgrade the operating system then try the next solution.
Installation Option 3: Attach the large hard drive to an add-in Ultra ATA PCI adapter card with a 48-Bit LBA compliant BIOS and controller driver. The adapter card bypasses the system BIOS and operating systems controller driver and uses its own BIOS and controller driver.
Using an IDE ATA/ATAPI controller that has a 48-Bit LBA compatible controller driver will allow safe use of large drives beyond the previous limits of 137 GB capacity. Additional controllers that do not have 48-Bit compliant drivers cannot safely access drives larger than 137 GB. A compatible card such as the Maxtor Ultra ATA/133 PCI for Windows and Sonnet Tempo ATA/133 PCI Card for MACs can be purchased at http://www.maxstore.com
(U.S. only) or at a local retailer.