Depending on your system the follow operations may be available:
Install: The solution is installed (beause it has not yet been installed)
Upgrade: The solution is upgraded without reinstallation
Repair: The solution is retracted from the solution store (uninstalled) and installed again.
Important:
If you are upgrading from a previous version of the Wiki Extensions, or are adding the optional components, you will have to make changes to the web.config.