>One way to implement that is by using the registry to keep track of when the program was installed. And whenever the program is executed, I can calculate the number of days. But the disadvantage is, I can change my system clock backwards and still use the demo. Any suggestions ? TIA!!

Sure.... Do this...

Dim InstallDate as Date

Text = GetSetting("MyPrograms",Title,"Install Date","")

InstallDate = Text

If InstallDate > Date then
msgbox "Date set back!!"
end if