Try using the full pathname of the executable:
C:\Program Files\Windows NT\Accessories\Wordpad.exe
C:\Program Files\Microsoft Office\Office11\WinWord.exe
These names depend on the Windows and Office versions you have. Search your C: drive if it still doesn't work.
Deming
Posted: Visual C# Express Edition, Starting a process with a non default application
After a lot of searching and expermentation, what needs to be done is this.
FilePath is the name of what process you wish to open the file, FileName is the name of the file one wishes to open. If the COMMA is not there it will flag an error.