Latest versions of Pest Patrol and AOL Anti-spyware (which is a rebranded version of Pest Patrol) have issues that prevent EssentialPIM from starting. Until Pest Patrol's vendors have issued a fix for it, we can provide you with a solution.

Download the following file EPIM.reg (please use right-click and Save As) to your computer, then run it. Windows will ask you if you agree to add information to the registry. Reply Yes.
The file adds EssentialPIM.exe to Pest Patrol's exclusion lists and is completely harmless.