The Virtualmin installer supports Ubuntu 10.04, the LTS release, but not Ubuntu 104.
My suggestion would be to use the automatic installer on Ubuntu 10.04, that makes things super easy
You can download the installer using the “Download” link above.
If you prefer using Ubuntu 11.04, it can be done, but is a lot more work, and requires a high level of Linux expertise to do that. You can read about performing a manual installation here: