Hi. Studio One V5 is a totally new installation that you can use alongside Version 4. Both versions are active and usable with no problems. However please be advised that songs you have made in version 4 can be opened in both versions but as soon as you save a v4 song in v5, you won't be able to open it in version 4 again. You should have your plugins found by v5 using your settings from v4, at least that is how it went for me. Uninstall at your leisure. You may want to keep both installed for a while. As I say, it will work with both installed perfectly fine.