Yes you need to use the same year program to amend. Yes you can install 2017 on all your computers. You can still update the program.
How to move to another computer.
The programs need to be installed from the CD or download them again. You don't need to install them unless you need to amend or open a return.
After you get the program installed the first thing to do before you open your tax return is to update the program and install any state programs you had. Then open your file. So you first might need to start a fake return to be able to download the state program (go to File-New Tax Return).
Then go to FILE -Open and find your return. You will need the tax file ending in .tax2017 to open in the program.
See this article on how to move your tax return to another computer…….
https://ttlc.intuit.com/community/tax-data-file/help/how-do-i-move-my-tax-data-file-to-another-compu...
How to amend 2017
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/00/27372
