If it were possible to use the same USB stick with another operating system, for example to store files to use on Windows, a virus in the other operating system could corrupt your Tails.
To store files in your TailsUSB stick, use the [[Persistent Storage|doc/persistent_storage]]. To exchange files between Tails and another operating system, use a separate USB stick.
If you worry that your Tails might be corrupted, do a [[manual upgrade|upgrade]] from a trusted operating system to upgrade it to a trusted version of Tails.
Editing the Tor configuration file, also called `torrc`, to modify how Tor creates circuits can weaken your anonymity in ways that are hard to understand and explain. That is why we don't explain how to modify the Tor configuration file in Tails, for example, to choose the country of your exit nodes or exclude some entry guards.
Still, you can close a given circuit and trigger Tor to create a new one using the [[New Tor circuit for this site|doc/anonymous_internet/Tor_Browser]] button of *Tor Browser* or the [[*Onion Circuits*|doc/anonymous_internet/tor/circuits]] utility.