(display resolution, size of RAM.) When you use an unified OS running inside a virtual machine you can prevent discovering most of the hardware related information. Various hardware information can leak through your communication.By reverting the state of the OS after each use either by using a live OS without permanent data storage or a virtual machine with non-persistent storage you avoid long-term storage of the information which could lead to your identification.Furthermore Tails is able to separate unrelated traffic into different Tor circuits. If it is possible it is transparently redirecting all traffic to the Tor network regardless of used applications and their possible vulnerabilities. OS like Tails makes information leaks less probable by not allowing clear-text communication.To be more secure you should use a complete secured operating system with unified configuration so that you cannot be identified when versions of various parts of it get revealed. The Tor Browser Bundle already solves this for the included software (Tor, Firefox, Vidalia Bundle). It is advisable to use least possible customized software. Various versions (and default configuration) of your software including operating system can be possibly identified from your communication.This should not be a problem if you use the Tor Browser Bundle properly as in most cases it should not leak the information which is stored outside of the bundle package.

Examples are: host name, IP address, state information and configuration of various applications. Your machine contains and collects information which could be used for your identification.The separate secured OS can also help you against possible information leak vulnerabilities in Firefox. Running a separate secured OS will give you advantages when you use other software with Tor than just the Firefox in the Tor Browser Bundle which is considerably secured. There are several anonymity concerns when you use your main machine for communication.

Torbrowser bundle