For example, the user-agent string of <span class="application">Tor Browser</span> includes <em>Windows NT</em> but this value preserves your anonymity even if you run Windows NT. On the other hand, changing this value makes you distinguishable from other users of <span class="application">Tor Browser</span> and, as a consequence, weakens your anonymity.
<p>If a software is not included in Tails, but is included in Debian, you can use the [[Additional Software|doc/persistent_storage/configure#additional_software]] feature of the Persistent Storage to install it automatically every time you start Tails.</p>