Problem updating X6 continued

I downloaded the update from the Endnote website, and the same curious problem occurs-when I attempt to install it, Corel Paintshop Pro opens, and I am unable to update Endnote. Quite a mystery, and a frustrating one.

I would be calling Customer or Tech support first thing Monday morning?  

Okay, but as today is Sunday, I guess I would look at what the extension of the install file might be, and then check your extention assignments.  Somehow that extension must have been assigned to Corel Paintshop?   

Googling problems of this type suggest a virus may have reassigned these extensions… I will keep looking, but see this as a starting point.  What operating system?

I suspect it is .zip or .msp that has been hijacked in this case?