system
6
Sandboxie is the best free sandbox i own, easy to use (i didnt figure the IU at first), good for running unsure files checking unknown emails (run browser in sandbox) etc and then gives the option the delete the sandbox, also if a malware is left in the sandbox it allows your antivirus to quarantine it, the only thing is the site list avast as a known conflict program
http://www.sandboxie.com/?KnownConflicts