1. Exit all Windows-based programs.
2. Click Start, type regedit in the Start Search box, and then press ENTER.
3. If you receive the User Account Control dialog box, click Continue.
4. Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
5. In the right pane, right-click Start in the Name column, and then click Modify.
6. In the Value data box, type 0, and then click OK.
7. On the File menu, click Exit to close Registry Editor.

Source:
http://social.answers.microsoft.com/Forums...f3-19d2b1a64187

Then go into your BIOS and set AHCI for your SATA drives. Upon boot Windows Vista or Win 7 will install the proper driver and you'll be set.

For Windows 7:


For Windows 8:

The Trim command should be enabled by default on Windows 7, but if you want to check to make sure do this:

Run "Command prompt" with adminstrator's right

Command prompt > fsutil behavior query disabledeletenotify

DisableDeleteNotify = 1 (Windows TRIM commands are disabled)
DisableDeleteNotify = 0 (Windows TRIM commands are enabled)