Yes. You can have both installed at the same time. To amend a return you did somewhere else or you don't have the original.tax file, you would first have to fill out Turbo Tax like you are doing the original return. You have to recreate the actual wrong original return. Then when it matches each line that you really filed you have to tell Turbo Tax you will mail it so it thinks it was filed. Then you can amend it. You will have to mail the amended returns. Mail them in separate envelopes.
You can buy the Desktop Download program directly from Turbo Tax here,
https://turbotax.intuit.com/personal-taxes/cd-download/
You can buy the Window's Business DIY program here…..
TurboTax® Business Desktop 2023-2024 | Tax Software Download