I think you'd be better off using
My.Settings[
^] than using text files to store this information.
Right Click on your Project in the Solution Explorer.
Select Properties. This opens your project's property pages.
Select the Settings Tab. This area lets you setup various settings that can be retained if your program is closed and restarted.
Add a property for Printer1, making the type
System.Drawing.Printing.PrinterSettings[
^].
Do the same for Printer2 and Printer 3.
Then in your code, before you do the If PrintDialog1.ShowDialog bit in each click event, check to see if the corresponding setting has data. If it does, then skip showing the dialog. If it doesn't, show the dialog to find it and set the setting so that the next time you will skip the dialog. You can access settings in code with
My.Settings.<SettingNameThatYouProvided>
Hope this helps.