Given your clarification in your comment (that you want to do this on the client machine), the answer is you can't. PHP doesn't run on the clients machine, it runs on your server and outputs to the clients browser, the browser then interprets that and displays the results, the browser doesn't run other applications as that is asecurity breach...except when downloading certain mime-types. If you are doing this with the users knowing cooperation, that might be a solution. If you control both code bases (the PHP and C#), then it's more likely, it would make more sense for the user to run the desktop app and for it to communicate with the PHP page to get the info it has.