An .ASPX file is a collection of processing routines written in Visual Basic Script. They are typically run from a web server or similar calling program by passing parameters into one or more of the routines.
If you try double-clicking the file, you are attempting to run it. When run out-of-context, e.g. not from a calling program, the .ASPX file can do nothing but damage.
If you want to see the underlying script commands, right click it and select Edit. The file should open in Notepad and you should be able to read the code.