Get rid of "The Publisher could not be verified. Are you sure you want to run this software"?

"To disable this dialogue box for ALL .exe files, you can add the following key to your registry:

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Associations]
""LowRiskFileTypes""="".exe

Note: this is not advisable, as it opens up your computer to other risks.

Other than that, ClickOff is your friend (a more general approach to such annoyances :)

ClickOff has been written out of a
personal need - like most programs
here. Questions like ""are you sure
you want to exit the program?"" made me
go insane after having seen them a
dozen of times.

ClickOff is developed to be the Swiss
Army knife for window handling, not
just a simple popup blocker.

Here are some key features:

Automatically clicks button on error messages that come up all the time.
Intuitive user interface.
Closes browser popups
Minimizes or maximizes windows
Delay times can be set to allow user intervention
Single buttons can be disabled temporarily
False clicks are avoided by taking the message text into the proccess of detecting.
To close windows that contain certain words, wildcards can be used
The scanning speed can be set
Can be disabled for a short period or permanently without having to be exited.
Has very low system resource needs, takes about 1 sec. to load and doesn't slow down the system while running.

ClickOff is freeware."

Another option is to delete the alternative file stream Zone.Identifier. This allows you to disable it from a particular .exe