Well, I don't know what you are trying to do, but what if your client is running a system where notepad.exe does not exist (Linux, Mac... - I would not be too sure)? (Beside the fact that this is not possible for security reasons as pointed out above).

If you want the user to read a text file, you can offer the file for download, and if he should be able to edit it, you can offer a multi-line text box to load the text (as well as upload a text file), and when the user clicks the Update button, generate a memory stream that he is able to store the file on his local computer. Is that what you are searching for?

Best wishes
Michael

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