Which version of Visual Build are you running? What does the expanded command look like (type Ctrl+M in the Command field to copy the value with all macros expanded, and also attach the problem .bld file)? That is the command that VBP will pass to a CreateProcess call. What is the error message reported? Be aware that if you're using redirection, piping, or command concatenation, you need to prefix the command with %DOSCMD% (see
http://www.visualbuild.com/Manual/?runprogramaction.htm).