You can download LyX 2.2.0rc1 from ftp://ftp.lyx.org/pub/lyx/devel/.
+For Windows users, if you installed a previous pre-release of LyX 2.2.0, you
+should uninstall that version before installing this newer release.
+
We hope you will enjoy the result!
The file lib/RELEASE-NOTES lists some known issues and problems compared