Our 2008 R2 IIS web server needs to be updated. We have some critical client applications running on it, so we decided not to apply any patches due to the downtime. Now we've accumulated a backlog of about 75 updates, some dating back to 2012!
What should I take into consideration when applying a large backlog of patches? I'm particularly concerned about one of the patches breaking our .NET Framework 4.0 applications.
(I'm particularly interested in hearing about any gleaming issues with IIS / .NET framework 4.0 and windows 2008 R2 updates you might have experienced that caused you to have to revert back, if any.)