do you have NCQ drive and a nforce MB??
Issues with NCQ SATA hard drives
I am using a SATA hard drive with NCQ technology on an nForce motherboard and I am experiencing problems. How do I fix this?
Several issues have been reported with hard drives supporting NCQ, possibly including long boot times. These issues are typically resolved with a hard drive firmware upgrade. Please contact your hard drive manufacturer for details on how to obtain and install a hard drive firmware upgrade.