Error Shown on Windows XP startup

Hey I just needed to know if any one has an idea regarding the following:
Each time I start windows XP Professional, I get the following Error Message.
It says "This installation package could not be opened. Verify that the package exists and that you can access it. or contact the application vendor to verify that this is a valid Windows Installer package."
I never tried to install any thing However this thing still pops.
