“The publisher could not be verified. Are you sure you want to run this software”.

To get rid of this error perform the following:
Start > Run > gpedit.msc
User Configuration > Administrative Templates > Windows Components > Attachment Manager
Add .exe to “Inclusion list for moderate risk file types“

Alternatively, if the file is opened from a network location you can add this network location to the Internet Explorer Local/Trusted sites category.

Windows Vista