WD Advanced Format drives are specifically optimized for Mac and the latest Windows operating systems such as Windows Vista and Windows 7 with a clean install. Advanced Format Technology is being adopted by WD and other drive manufacturers to increase media format efficiency, thus enabling larger drive capacities.
Using your WD Advanced Format Hard Drive with a Windows Operating System may require you to run the WD Align Windows software utility after you install your operating system or partition and format the drive as a secondary drive. The WD Align software aligns existing partitions on the Advanced Format drive to ensure it provides full performance for certain configurations. (Please see table for configuration details)
If your operating system is either Windows 7 or Vista, WD recommends using the latest Intel driver version 9.6 or later for maximum performance in all situations. Please visit Intel for the latest driver downloads.
Got from there site
Advanced format seems to be for Vista or Win 7 not XP You would need to reformat the drive.