There was a problem sending the command to the program

I have Windows 7 Professional on a 64 bit machine. When I double click a .tex file with scientific workplace open, I receive the message:

"There was a problem sending the command to the program"

and the .tex file does not open. After running Scientific Workplace, I am able to open a file using the file --> open commands.

Do you have any advice on how to fix this?

Try running the program once

Try running the program once as administrator as described at #737: Using SWP, SW, or SNB with Windows Vista or Windows 7/8 in the Startup message section.  I haven't seen this problem, but it could be another side effect of the original issues discussed in the article.

I set it to run in XP mode

I set it to run in XP mode when I initially installed SWP,

When I double click on the SWP short cut I get the following message:

User account control: Do you want to allow the following program from an unknown publisher to make changes to this computer?

which I always say yes to.

Do you have any thoughts on the "User account control" message?

I turned on XP mode and see

I turned on XP mode and see the UAC dialog, so it's a side effect of XP mode.