Hi Rick,
Thanks for the reply (disappointing though it is).
The problem is that I have to run SAP NetWeaver Business Client 5.0 to do my timecard. After Paint.NET upgraded the .NET level to 4.6, SAP refused to run anymore, displaying an error saying that .NET 4.5 must be installed. So I thought fine, I'll just reinstall .NET 4.5. But the install for that says it won't run because a newer version is already present. Well, if I can't do my timecard, I don't get paid, so the SAP client is going to win out in this situation ;=) I uninstalled .NET 4.6 and reinstalled .NET 4.5. Now SAP is happy but Paint.NET refuses to run.
It's a shame because I really liked Paint.NET. Very intuitive and feature-full. But I guess that leaves me looking for another free image editor. Any suggestions?