Does Windows 7 actually defragment an SSD drive if you tell it to?

By default, Windows 7 should automatically disable its scheduled defragmentation—but unfortunately, I’ve seen too many cases where the built-in Disk Defragmenter was still enabled, despite the fact that an SSD was built-in! Users should make sure that it’s disabled. Here’s how: Go to the Start menu and click on “All Programs”, “Accessories”, “System Tools” and “Disk Defragmenter”.

(Quoted from the Tune-up blog).

Microsoft confirm this here:

Windows 7 usually detects SSD disk after this has been installed or connected and integrates it properly. This also includes the detection that some services are disabled, which would restrict the functionality, performance and service life of the drive. First of all, you should check whether the automatic defragmentation is disabled. This is not the case, you should disable the automatic deactivation for the disc manually.

From these quotes I conclude that performing a defrag will actually do what it says (otherwise the warnings would be senseless).