ASRock motherboards support 48-bit LBA mode hard drive. At present, ASRock motherboards have no limitation for the capacity of Hard Disk, so you can use over 127GB or 137GB Hard Disk on them.
If you want to get a full capacity under Windows XP/2000, please make sure that your operating system can support 48-bit LBA mode. Please refer to the following link:
http://www.asrock.com/support/QA/TSDQA-01.pdf