Launch 3D Builder. Click Open > Browse for models . Select your broken STL file.
3D Builder is a beginner-friendly 3D modeling and editing application that, while no longer pre-installed in Windows 11 as it was in Windows 10, remains a highly effective tool for hobbyists and 3D printing enthusiasts. Availability and Installation in Windows 11 3d builder windows 11
3D Builder is a lightweight, beginner-friendly modeling and editing tool originally developed by Microsoft for Windows 10 and 11. While it has recently been removed from standard pre-installations and deprecated by Microsoft, it remains a highly regarded tool for quick mesh repairs and 3D printing preparation. is 3d builder still available on windows - Microsoft Q&A Launch 3D Builder