From a recent real submission to the AutoCAD Product Feedback web form and responded with a solution by Misha of the AutoCAD Team. It is a fairly common problem when a registry cleaning tool goes overboard and removes required data for a program.

Problem: "There are not properties listed in my  "properties" dialogue box when I click  on an item."

Solution: Usually this is caused a external application that cleans Windows registry settings and data.  To restore AutoCAD behavior you will have to reinstall the program or repair its registry.  No need to uninstall and install again.  Just choosing Reinstall or Repair option in the Windows > Control Panel > Add or Remove Programs >AutoCAD should do the trick.