Digidesign's excellent Strike and Velvet instrument plug-ins for Pro Tools each require that you install sample content (the actual sound samples used by the plug-in) in order to use them. Strike's content requires more than 6GB, while Velvet fills over 600MB. Neither of these are HUGE in today's world where sample libraries can top 500GB with ease. But, if you have a smaller hard drive - like those found in many laptops - the space required may be precious.
An option is to move the sample content to an external drive. But note that with Velvet and Strike, there's an extra step involved: You have to let the plug-ins know where the libraries are located.
Fortunately, both plug-ins install a small application entitled "Set Velvet Content Location" and "Set Strike Content Location" (depending on which plug-in you're using). After placing the content library where you want it, copy the small "set location" app to the same directory. Then double-click the "set location" app to run it.
A dialog box will open, which will display the path to the content library. If the path is correct, click OK and you're ready to use the plug-in!