When we began moving from .Net 3.5 to 3.5 with SP1, we started encountering issues where the update was failing on many workstations. Although we were able to work around this by uninstalling all versions of .Net , this was too lengthy a process and also had to be done a case by case basis. When you install .Net, a series of setup logs is written to C:\Documents and Settings\username\Local Settings\Temp. The answer for us resided in dd_NET_Framework30_Setup####.txt, the .Net 3.0 component that could not be uninstalled.
Why is the setup failing? Behind the scenes, the .NET Framework 3.5 SP1 attempts to uninstall older versions of the .NET Framework 2.0, 3.0 and 3.5. The removal of 3.0 is failing because one or more of the msi files it needs to perform the uninstall cannot be found.
When a .Net setup fails, you can find an entry in the Windows Event Viewer. It won’t tell you what is missing but it will tell you which log to look at: Read the rest of this entry »