If you are installing Citrix XenApp 5.0 and creating a new farm do not install .NET Framework 2.0 Service Pack 2, as doing so will prevent the XenApp Delivery Services Console "Run Discovery" from finding the farm. Citrix does not have a workaround for this yet and your only option will be starting over with a clean Windows installation.

Once Windows 2003 SP2 is installed it’s OK to run Microsoft Update and install the required updates, just don’t select the optional updates to .NET Framework 2.0 Service Pack 2 or .NET Framework 3.5 Service Pack 2.

A link to a relevant discussion thread on the Citrix Support Forums can be found <a href="http://forums.citrix.com/thread.jspa?threadID=269396&amp;tstart=0">here</a>.