People often ask me for suggestions on how best to upgrade
from previous betas of Visual Studio 2008. In general I'd recommend
uninstalling the Beta2 bits explicitly. As part of this you should
uninstall Visual Studio 2008 Beta2, .NET Framework Beta2, as well as the Visual
Studio Web Authoring Component (these are all separate installs and need to be
uninstalled separately). I then usually recommend rebooting the machine
after uninstalling just to make sure everything is clean before you kick off
the new install. You can then install the final release of VS 2008 and
.NET 3.5 on the machine.
Once installed, I usually recommend explicitly running the
Tools->Import and Export Settings menu option, choosing the "Reset
Settings" option, and then re-pick your preferred profile. This helps
ensure that older settings from the Beta2 release are no longer around (and
sometimes seems to help with performance).
Note that VS 2008 runs side-by-side with VS 2005 - so it is
totally fine to have both on the same machine (you will not have any problems
with them on the same box).