I discovered, at last, that my search for AHCI mode, in order to be able to enable the TRIM command for a better use of a SSD, was useless, as the SATA Controller of the Toshiba Satellite A200 laptops is set to AHCI by default as stated in this topic: TOSHIBA SUPPORT FORUMS :
Satellite A200 or Satellite Pro A200 series does not contain the option to change the boot mode between AHCI or compatible mode.
The SATA controller is set to AHCI by default.
Afterwords, as root user, in (Windows 7) Command Prompt, I typed: fsutil behavior query DisableDeleteNotify obtaining 0, which means that TRIM is enabled.
This message was posted on behalf of Intel Corporation
We understand you were looking for AHCI driver, however as you found out, in your computer the mode in BIOS comes by default.
We are glad to see you have checked and TRIM is enabled.
Please let us know if there is something else we can help you with.