I you want to uninstall IE8 and it won’t uninstall through add/remove program. Should apply to beta and release candidate (that was where I needed it). Program didn’t show up in add/ remove, but could be uninstalled through %systemroot%\ie8\spuninst\spuninst.exe.
I had to use this procedure since I first installed the beta. When I tried to install the final version, I wasn’t able to upgrade.