PHANTOM ERROR MESSAGE

I have a Dell Inspiron 7500 laptop running NT4WS SP6A that has an error message that comes up after login. It states “Cannot find File ‘E:\Program’ or one of it’s components…”. We have searced all startup folders, all registry keys, Win.ini, System.ini, all to no avail. We are out of ideas. The system halts until you click on the ok button, but then it continues normally. No messages in the error logs either. We welcome all suggestions. Thank you.