This section provides user suggested tips that aim to increase Qubes OS usability, security or that allow users to discover new ways to use your computer that are unique to Qubes OS.
To increase both security and usability you can set an AppVM so that it automatically opens any link in an different AppVM of your choice. You can do this for example in the email AppVM, in this way you avoid to make mistakes like opening links in it. To learn more you can check [security guidelines](/doc/security-guidelines/) and [security goals](/security/goals/).
If you want this to happen automatically you can create a .desktop file that advertises itself as a handler for http/https links, and then set this as your default browser.
Replace `APPVMNAME` with the AppVM name you want to open links in. Now save, in the AppVM that you want to modify, this file to `~/.local/share/applications/browser_vm.desktop`
Finally, set it as your default browser:
`xdg-settings set default-web-browser browser_vm.desktop`
Suppose that you have within a not so trusted environment - for example, a Windows VM - an application that tracks and reports its usage, or you simply want to protect your data.
Start the Windows TemplateVM (which has no user data), install/upgrade apps; then start Windows AppVM (with data) in offline mode. So, if you worry (hypothetically) that your Windows or app updater might want to send your data away, this Qubes OS trick will prevent this.
You can also add the `discard` option to the mount line in `/etc/fstab` inside the standalone AppVM if you want trimming to be performed automatically, but there may be a performance impact on writes and deletes.
