each online account can only be used for one return, if you do another return on the same account, the first return will be overwritten. If you need to do more than one, you should consider getting the Download/DVD version. You can efile up to 5 returns and do an unlimited number for paper filing.

But you can not install the Desktop program on WIndows XP anymore so you would need to find another computer.

The Online version is only good for 1 return. But you can use the same email address for 5 accounts.   How to start another return in the Online version
<a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/1894512-how-do-i-start-a-second-return-in-turbotax-online">https:/...>

Or if he or you have a simple return you can use Tax Freedom which opens in January.  The Turbo Tax Freedom website is free for federal and state.  And has more forms than the Federal Free Edition, like the full 1040 return and Schedules A, B, C , D, E, F, EIC, H, K-1, SE,  etc.

To qualify for the Tax Freedom website  you just need to meet one of these 3 things
AGI $31,000 or less
Active duty military with AGI of $64,000 or less
OR qualify for EIC (earned income credit.)

In order to use the Tax Freedom Edition, you have to start it at a special website:
<a rel="nofollow" target="_blank" href="http://turbotax.intuit.com/taxfreedom/">http://turbotax.intuit.com/taxfreedom/</a>

<a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/1901571-minimum-system-requirements-for-turbotax-windows-software"...>