windows 7 - "Open file with" dialog upon startup?

Every time I login to my PC, I receive this message:

Now, it's not that big of a deal, and Windows 7 works just fine. What's odd is that it's supposedly just a generic 'Program' that 7 is trying to open. It's done this since I installed it. I've not downloaded any viruses or anything like that.

Can anyone help me resolve this?

Answer

You likely have a file named Program in the root of one of your disks; for example, C:\Program.

You also have a startup entry with missing quotation marks, pointing to C:\Program Files\Random App where it should be "C:\Program Files\Random App". Such an entry lacking quotes can be parsed in two different ways – in this order:

1. Path "C:\Program", two arguments "Files\Random" and "App";


2. Path "C:\Program Files\Random App", zero arguments.

This is a mistake by the program developers, but it usually goes unnoticed due to file existence checks done by Windows – it just goes to the second option most of the time. However, when "C:\Program" does exist, the first option becomes valid as well, and Windows attempts to open the file.

Windows XP used to warn the user about the existence of such files at logon time. I haven't tested if Windows 7 displays one, though.

As for how the file was created in the first place – the cause might be similar; even fairly recent programs (and, well, users) sometimes have the 1970's idea that File Names Shall Not Have Spaces...