Installing berrybrew will have no impact at all on the installation of any existing software (including Perl installations).

It manages instances of its own portable Strawberry Perls, each which are fully contained within their own directories, and are stored and operated out of a location far away from any other software.

If you install and switch to a new Perl using berrybrew switch, then the Perl you've switched to will become the one in use on the system via the PATH environment variable, but you can disable it very quickly with the berrybrew off command to go back to using your previously installed (aka "system") version.

Recently, I added the berrybrew virtual command, so that berrybrew can allow you to add your existing Perls to berrybrew so you can use its switch and use commands with them directly as well (again though, it does NOT touch those installations; it essentially just updates a JSON file with the path information of it).

I've been working very hard on the next version which will have an even more robust installer system than I have now, and it'll also include a Windows System Tray icon allowing one to switch between Perls within the UI, and eventually provide UI widgets for most of the berrybrew operations, and the ability at install time to choose where you want the Perl installation root directory be placed (currently it defaults to C:\berrybrew with an obscure way to change it if wanted).

One more significant addition to my last version is the introduction of the berrybrew-refresh command. Run it after you've used berrybrew switch to switch to a different version, which keeps you from having to close the existing CMD window and open a new one.

Version 1.30 will be released just before Christmas as a Happy Holidays gift to all of the Windows Perl developers out there (interestingly enough, I'm not one of them... I develop the software in a language I have no other use for, for users on a platform I don't even work on myself) :)