I have seen some errors in the software when upgrading the systems, so that is why I still have a WinXP machine at home just in case I need it.

Some of the old ones don't play nice with Win7.

I am sure that same occurs with Win10. 2009 is quite old, so you might want to keep the old PC just in case. You don't need internet connection any more since you can't e-file that far back.