In Microsoft Windows XP I can go to Control Panel and choose Add/Remove Programs. Once the list is populated you can sort by different values. One of the values is Date Last Used. How is this date determined? It never seems to relate to when I actually last used a product. Also, how is the Frequency of Use determined. Again, it never seems to relate to how often I actually use a product. This has been a curiosity in the past, but I would really like to know, so that when others ask me I can give better advice and/or not make a bad decision if looking at someone else's PC. Thank you!