I have 2 computers -- I prefer this one but I fear it may die -- if it does die can I switch to other one and resume?

If you are using the TurboTax online web-based editions you can sign onto the TurboTax online account from any computer.

If you are using the TurboTax desktop edition software installed on your personal computer, you can download another installation file to a new computer, but you will need your license code to install the software.

Sign onto this website to download the installation software - https://accounts.intuit.com/app/account-manager/productsBilling/turbotax

Additionally, you will need to copy the contents of the the TurboTax folder in your Documents directory to the new computer.

TurboTax Desktop can be installed on up to five computers.

However, you cannot resume the work you did on one computer on another computer because your tax file is only saved on the computer yo used tp prepare it. 

To continue the same return on another computer, you need to save the tax file (with extension taxxxx) on a mobile device and transfer it to the new computer.