Software or memory problem ???

I have a Compaq Presario V6000 notebook that I am using for my company. I loaded the Microsoft Streets & Trips 2007 program in and it worked just fine. Since I do estimating for my company, I loaded disk that came with a book that I use. National Electrical Estimator is the program and it works great. My problem is that when I create an estimate and then save it. When I try to open it again, I can't. Something pops up and tells me that the program can only be opened with Streets & Trips.
I removed the Streets & Trips program and the problem went away.

I really want to have these two programs in my computer and can't figure out why they will not work together.

Has this happened to anyone else or does anyone know what my problem could be?

Thank You,

John