I believe that HP doesn't provide that option in its older computers ( don't know if they do in their newer computers or not ). They instead use a third party software from Condusiv ( ExpressCache - 3x Your PC Speed | Diskeeper ) to provide the accelerated drive functionality. If you have performed a system recovery, You may or may not find the installer in your C:\ SWSETUP >> APP>> Applications >> Condusiv folder.
That being said, a 128GB SSD to provide acceleration is a waste, You may as well install the OS on it.