External eSATA not recognized

[shiffman]

Running Win 7 on TP 4100. Have gotten a new external drive (actually 2 in a RAID 1 box). Everything works via USB connection, and was able to initialize and partition drive(s) and copy files, but when I connect via eSATA cable, system just does not see the drive. BIOS already has AHCI as the mode for SATA drives, and I applied a Microsoft patch that I gather loads AHCI drives at boot-time. But can't get this to work..

HELP!!

Thanks in advance

Saul