PROBLEM: Cannot open images in Paint Shop Pro when using Windows Explorer (Win 7, 64bit)
DETAIL: Error message "problem sending the command to the program"
SOLUTION: Here is what worked for me.
I know this response is coming in months after the original inquiry but I thought I would share what worked for me with this problem. I have been using Paint Shop Pro X successfully with Win 7, 64bit until this morning when I discovered (suddenly) that I could no longer click on an image in Explorer and have it load in PSP X. Instead, I received the "problem sending the command to the program" followed by the PSP application opening but no image appearing. I believe that a Windows update of some sort took place the night before - I remember seeing it shortly after shutting down, delaying the actual shut down process (only mentioning this because I'm not sure if it reset some things I'd done a custom set up on). Up until this morning, I wasn't experiencing this problem. Anyway, what I did was:
Right click on the PSP X icon, select properties, re-establish my administrative rights, but also UNCLICK the "Compatibility mode" check box AND unclick "run as an administrator" --both in the Compatibility panel under PSP X properties. I then clicked Apply and Okay, then re-opened a fresh Explorer window
I have not had a problem since.
I'm no Win 7 expert and to be honest, while I like some of the features, all of the compatibility/User rights mumbo jumbo often requires me to google more questions to find the right answers (and I usually don't find uniform solutions) than it does serve as a good, intuitive interface (and least for this 47 year old's intuition). Nonetheless, I know there are a lot of us out there that cannot replace all of our old software right away (and some software that we've mastered over the years still does its job so why change?). For older versions of Paint Shop Pro, which just today launched X4, hopefully this process will do the trick in restoring the click images in Win 7 Explorer and open in older versions of Paint Shop Pro process.