Install Windows XP or Windows 7 in VirtualBox or VMware. Then install MathType 5.2 (if you have the original installer). This is the most reliable way to edit old equations.
If you’ve found yourself searching for a “MathType 5.2 registration key,” you’re likely in one of three situations: mathtype 5.2 registration key
Equatio is excellent for STEM and includes handwriting, speech, and LaTeX input. The free version covers basic equation needs. Install Windows XP or Windows 7 in VirtualBox or VMware
The registration process for MathType 5.2 differs significantly from current versions because it is a legacy product originally released in If you’ve found yourself searching for a “MathType 5
The current version integrates directly into the Microsoft Marketplace as an add-in. You can install it via the "Insert" tab and "Add-ins" section in Word.
Stable on legacy OSes. On modern Windows 10/11, you may encounter compatibility issues (e.g., Word 2016+ crashes, missing fonts). No longer officially supported.