With the release of SharePoint 2013 SP1, Server 2012 R2 is now supported.
With this release I wanted to try to upgrade my dev environment to Server 2012 R2.

My dev machine has all roles, so AD, SQL and SharePoint. The steps below I used to upgrade the machine.

1. Install SharePoint SP1 as you usually install an update
2. Make sure you have enough free space, I needed 12GB.
3. Mount the ISO of Server 2012 R2 and run the following command
   ‘adprep /domainprep’, the adprep command can be found on the disc in the folder ‘\sources\adprep’
4. Run the installation with setup.exe and choose for upgrade
5. After the upgrade everything seems to work, Central Administration worked, but my Web application had an issue with the Security Token Service
   
6. I fixed this by reprovision the Security Token Service

   $sts=Get-SPServiceApplication
   |? {$_ -match
   “Security”}
   $sts.Status
   $sts.Provision()