Assembly version, File version, Product version
If you are a .NET developer, Assembly and File version would be familiar to you. They can be set in the Designer UI (project Properties page, Application tab, Assembly I nformation button...) which basically updates appropriate attributes in AssemblyInfo.cs. Now, there is a less well known number - the Product version . It is not well documented and most developers ignore it altogether with no side-effects most of the time. However, it is an important number and it seems that, of the three, Product version is the most widely used. The three version numbers simply take the values you give them or: a. If Assembly version is not explictly specified, it takes the value of 0.0.0.0. b. If File version is not explicitly specified, it takes the value of Assembly version. c. If Product version is not explicitly specified, it takes the value of File version. In Windows Explorer of Windows XP and Server 2003, you can see from the properties of a file all three version numbers. In W...