As for using it on windows, you need orx-dev-mingw-1.2.zip.
However the latest version of mingw (that you can get on http://www.mingw.org) won't be compatible with the binaries from the 1.2 package.
Basically gcc 4.5.0 doesn't work with any library compile with gcc 3.x or 4.0.x. You need either to get an older version of mingw or compile orx yourself (by getting the -src- package or by syncing the svn repository which has already up-to-date external libraries for mingw/gcc 4.5.0).
Comments
As for using it on windows, you need orx-dev-mingw-1.2.zip.
However the latest version of mingw (that you can get on http://www.mingw.org) won't be compatible with the binaries from the 1.2 package.
Basically gcc 4.5.0 doesn't work with any library compile with gcc 3.x or 4.0.x. You need either to get an older version of mingw or compile orx yourself (by getting the -src- package or by syncing the svn repository which has already up-to-date external libraries for mingw/gcc 4.5.0).