Sandboxie requires neither the disabling nor blocking of functions available to Web sites through the browser. Instead, Sandboxie isolates and quarantines the outcome of whatever the Web site may do to your computer, including the installation of unsolicited software. There is no trade-off of functionality for security: the Web site can use the full range of active content tools, and if it uses these tools maliciously to install software or otherwise make changes in your computer, then these changes can be easily undone.
Sandboxie intercepts changes to both your files and registry settings, making it virtually impossible for any software to reach outside the sandbox.
Sandboxie traps cached browser items into the sandbox as a by-product of normal operation, so when you throw away the sandbox, all the history records and other side-effects of your browsing disappear as well.