Actually, this is the exact query that I got:
In my system all exe files are being opened with notepad!!!
Thats more or less what I got in a conversation a few minutes ago. Now, this particular question isn’t particularly new, and it can be caused by an overzealous tinkerer or a malicious code (if you haven’t done anything, truthfully, and this happened to you, please check it out with an antivirus).
The problem, if you want to understand is that Windows is designed so that every file is expected to have an extension. That 3 letter ending tells the Windows OS with which program to open the file with. So if you have .txt file, you should open it with Notepad.exe.
Now what about a .exe file? Who opens that? The answer is simple: Itself! Hence you have to tell the OS (through the Registry Editor), to open the .exe file with itself. Hence “%1” %* as the open with command, which indicates that the file needs to be opened with the same .exe (%1), and having the same arguments (%*) that it was assigned.
Anyway, in order to fix this, please follow the following instructions..