Just for the hell of it, I typed excel(or excel.exe) at the command line and excel started up. FYI winword.exe does not start. which /a excel.exe shows: excel.exe is an external : C:\Program Files\Microsoft Office\Root\Office16\EXCEL.EXE Looked at the path and saw nothing that would result in this. unalias * Still starts. Unset path will not start. get normal path and Start trimming path and get to last entry that points to an java directory. Delete the last item in path, and it will not start. Add that item back to path and it will start. Edit that path to an invalid path and it starts. Now It get strange now; unset path. will not start. do an Path 1 ( and invalid path) and excel starts. unset * excel will not start add any path valid or not, and excel trys to start, but I get an box saying error unable to start. summary, no path and excel.exe will not start from command line. have any path (invalid or valid) and excel.exe will start from command line. PS I have NOT been drinking.... Excel will NOT start from CMD.EXE.