Make sure ClearType is the same for recording and playback (a real problem if the playback machine is a different machine than the one you recorded on).
(Note: Image comparison should be a last resort because there are too many things that can go wrong)
How to set ClearType on Windows 7:
- Right-click in desktop
- Personalize
- In bottom/Left, Display
- In Top/Left, Adjust ClearType text
On Windows 10:
- Right-click in desktop
- Personalize
- In Top/Left, Find a Setting Box”, type literally, “Adjust ClearType”, but no quotes.
If you are VM'ng, the "Font Smoothing" on the "Experience" tab shown below in attached rdp.png is what turns on "ClearType".