You can only install the TurboTax software that you purchased on computer that you own. Releasing the software you purchased to someone else is a violation of the End User License Agreement for the desktop software.
Go to this TurboTax website for INTUIT SOFTWARE END USER LICENSE AGREEMENT TURBOTAX DESKTOP SOFTWARE—TAX YEAR 2017 - https://turbotax.intuit.com/corp/license/desktop.jsp
You can create, complete and file a tax return for anyone you wish using the TurboTax software installed on your personal computer. However, the software is not licensed for someone charging a fee to prepare a tax return using the TurboTax personal desktop editions software.
