I would suggest RRTrains which is a free shareware software downloadable setup.exe file. I have been using it since 2006 for my Piedmont Division RR inventory. It also offers the ability to export the database to a comma delimited file type for use in spreadsheet applications like Excel.
http://www.gregorybraun.com/RRTrains.html
Here is the information from their site about the small program:
RRTrains 2000 is a small program used to create a detailed inventory of
your model railroad collection. RRTrains 2000 will record information about each
locomotive and piece of rolling stock in your collection.
Along with catalog
and model information, you can also record acquisition dates, prices and current values.
Several inventory
reports can be generated and printed, an option is also included to print lists of items
for sale. The inventory reports you generate can be displayed as standard HTML web pages.
RRTrains 2000
includes a sample inventory database to fully illustrate how model railroad collections
can be inventoried with this easy-to-use program.
RRTrains 2000 will
run on MS Windows XP and Millenium Edition as well as MS Windows 2000 and 9x/NT systems.