If I download the installer will this let me back into Qucikbooks 2018 so I can link companies? If I use trial version of Qucikbooks 2021 does it become a 2021 data file and have it so I am actually using 2021? I am never confident in trial version being "forever" than if I get 2018 going it tells me I have a 2021 file that cannot be used or converted.

Thanks again for your help