If you install Visual Studio 2008 Standard Edition after running the VS 2008 Professional 90 day trial you may get a package load failure when you start the Standard environment.
The error message recommends running "devenv /resetskippkgs" from the command line, but no location is specified and the path was not recognized on my PC so the command did not run
For visual studio 2008 the command is found in the C:\Windows\Microsoft.NET\Framework\v3.5 directory. Make sure you have shut down any open instances of VS before running this command. The command will open a new instance, which I closed immediately in order to save the updated settings. No more warnings about packages since then