Are SP server web config files changed after an SharePoint update/patching

Question

Its maybe a stupid question for someone, but I was wondering if a SharePoint update does change a web config file content. I want to do some changes over some of our SP servers web config files and I was not sure if those changes are going to be lost/reset after I do a SharePoint patching. Exactly does the SharePoint wizard do those changes or not?

Thanks!

Answer 1

They can be in addition to making certain changes/retracting/deploying Web Applications. You shouldn't be updating web.config files by hand but instead using the WebConfigModification class to make the alterations. There are implementations of this via PowerShell script.