first PATA is parallel ATA, you DO have parallel ATA on your mother board, after SATA was released in 2003, ATA was renamed PATA, please read up on it
http://en.wikipedia.org/wiki/Parallel_ATA
if MSI says it can't boot from SATA, you're out of luck, however, you could place the boot sector on the PATA drive, then after the boot sector is read, and gets going, have boot.ini point to your SATA drive. then you could remove everything from you PATA drive except the parts that boot and point to the SATA drive, freeing up most of the space for data.