Outlook Express Unable to start the program

Microsoft outlook express is the email client that I have been using from long. When I try to start Outlook express on my PC today I got an error message.
Below is the screen shot for all your reference.
Outlook Express
Unable to start the program. One of the required components may be busy or missing. Please check your installation and try again.
This error started occurring after I installed Network Associates International's Pretty Good Privacy (PGP) program on my Windows XP machine.
Has this anything to do with the PGM or something with the settings?
