This is an annoying issue with Word 2007 that I came across the other day whilst at work, which is actually fairly simple to fix.
The scenario I was having was that I would open up a Word file (either .doc or docx) and would then get the following error message resulting in the document being unable to open.
“There was a problem sending the command to the program”.
The way to fix this is to is to use the built-in Office tool for Word along with the command switch /r that will force a re-register of Word in the Windows registry. Here is how to do it:
First, close all instances of Word that may be running. Now click on Start and type winword.exe /r and hit Enter
This will automatically start Word, start Set up, makes changes in the Windows registry, and then quit. This switch (/r) forces a re-register of Word in the Windows registry.
How long this process will take depends on the speed of your computer, but it should only be about 30 seconds or so.
Another workaround for this error, is to run Word as the administrator by right-clicking on Word via All Programs>Microsoft Office>Word>Compatibility (200*)>Run this program as administrator, as sometimes this can cause an issue depending on which error you are seeing:
Now you should hopefully be able to open the files again without issue.