Heartland

Andrew save the following green text into a file called fix.reg (use notepad and remember to not save as .txt). Then double click it to install it to your registry. This should stop whatever is preventing your .exe. files from running (AVG, etc). Once you've done this try malwarebytes again. This method has worked for me and several others I've suggested it to (including one absolute PC numpty!)

I got the instructions here

Windows Registry Editor Version 5.00

[-HKEY_CURRENT_USER\Software\Classes\.exe]
[-HKEY_CURRENT_USER\Software\Classes\secfile]
[-HKEY_CLASSES_ROOT\secfile]
[-HKEY_CLASSES_ROOT\.exe\shell\open\command]

[HKEY_CLASSES_ROOT\exefile\shell\open\command]
@="\"%1\" %*"

[HKEY_CLASSES_ROOT\.exe]
@="exefile"
"Content Type"="application/x-msdownload"