Does your computer meet the system requirements for the software?
https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-...
There was no license code or number for 2018 desktop software. The license codes began with 2019 software.
Try contacting customer support for help with installing your software.
To call TurboTax customer support
https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number
Customer support is available from 5 a.m. to 9 p.m. Pacific time
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
