Yes, you can't open the program. But what EXACTLY happens when you try the Reader icon on your desktop? You told us you got the same message but that's hard to understand.
Please post a screen shot of the message when you try to start Reader NOT open the PDF. It may be similar but it's inconceivable that it will be word-for-word identical. These details matter.
Please tell us exactly what happens when you try to run Reader NOT open the file. If you get a message please share it. if you would like more details on what I'm asking please say.