The 2018 program only needs the .tax2017 file to transfer the info ... the 2017 program is only needed if you want to open the 2017 return. You should be able to move the installation file for the 2017 program to the new computer if you didn't delete it so you have it if you need it in the future. If you stil have access to the old computer you may wish to open the 2017 program and save the return as a PDF as well for future reference ... then move it to the new computer as well.
