Just got this in an email:

"How do I know if TRIM commands are working in Windows 7 on my Solid State Disk?

In an elevated command Prompt (IE – run as administrator), type the following:

fsutil behavior query disabledeletenotify

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