Strange new installed programs

This topic belongs somewhere else but no named forum seems appropriate so I post this here.  A moderator should move it to whatever is the right place.

 

We suddenly find a Weather Channel Desktop (not actually on the desktop),  and a Playsushi browser add-on.  The playsushi thing seems to be related to some terms found in some webpages that contain double-underlines which when mouse is positioned on the link, brings up a "Playsushi Entertainment" window with other links on it. 

 

Does anyone know about these two things?  I strongly believe that they are some form of adware. 

 

System:

Windows 7, Internet Explorer version 8