If you're getting this error message (which reads along the lines "Your administrator has blocked this application because it potentially poses a security risk to your computer" and looks similar to this screenshot) and can not get past this and launch ICMIZER.
It is caused by "Click Once Trust Prompt Behavior" which is described in detail here https://msdn.microsoft.com/en-us/library/ee308453.aspx
Generally, you need to edit Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel\Internet and change it to "Enabled"
To do this press Win + R on your keyboard (to get the Run dialog, see below), type in regedit.exe (or launch regedit.exe some other way) and press ok
Here you can see how you can locate the required key in regedit: