Greetings to all

I have started using VFP8 and started to create install cds using installShield.
For example when I make an install cd of payroll system and install it on a computer, everything is fine. Then when I make another install cd for accounts and try to install it on the same computer, an error comes up and asks me to remove the previous software to install the accounts program. I have read the help files and found out that I have to change the version number and upgrade number. Do I have to change these numbers everytime I make an install cd or is there a better way ???

Your help will be appreciated. TIA
Shafid