I've used the delete tool to remove v1, but everytime I run the v3 installer it will still open a v1 window.
For installing Solar-PuTTY v3 just launch the installer. You can check the installed version in Menu->About dialog.
Solar-PuTTY v3 is installed to %USERPROFILE%\AppData\Roaming\Solar-PuTTY-v3\
Richard