I recently spent too much time trying to get an ADFS Server upgraded, in my case from Windows Server 2008 to 2008 R2. Like many SharePoint folks that are just trying to get along in a claims happy world, seemingly simple things like this can cause a surprising amount of churn. Here are some tips that may help you get through it:
Hope this is helpful to you.
Unfortunately, this tip does not work for Server 2012 (ADFS 2.1), as the restoration of the AdfsConfiguration database will fail, unable to validate the Schema. For those upgrading from ADFS 2.0 to Server 2012, follow this Technet guidance: