So given the amount of responses not many seem to use the nightly windows version then ;-) Or are just click-happy.

A lot of people use the nightly builds but I guess they just bookmark the page and click two times, one to download and one to install.

Is a bit complicated as the installer name is variable each day. I'll see what I can do.
Probably I can generate a DownloadAndInstall.bat and put it in the same place as the nightly-builds.

Oh I was given the impression that Windows users always need to deinstall the nighlty in order to install a new one. I guess that part is the most cumbersome. Still having a simple bat file on the desktop would help :-)

Or just shipping OM with rsync.exe? Then you could really script the update by just keeping a copy of the extracted files. There is no need to env.vars, etc anymore after all (and we could have 2~3 different directories; nightly, stable, release).

@dietmarw: the installer will uninstall the already installed OpenModelica automatically.
@sjoelund.se: rsync is not very friendly on Windows.

Maybe we could have an Windows start menu item or a menu in OMEdit: "Update OpenModelica" which does the update automatically.

What's wrong with rsync on Windows? cygwin needed?

How about http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp ?