SolidWorks 2012 requires .NET Framework 3.5 SP1 (including 2.0 and 3.0). On Windows 10/11, this feature is not enabled by default.
If the registry fix does not work, the actual installation files on your hard drive may be corrupted. Using the SOLIDWORKS Installation Manager to "Repair" the installation can replace missing library files. error cannot initialize library solidworks 2012
Sometimes the installer fails to register COM libraries. Use regsvr32 to force registration. SolidWorks 2012 requires
Download the .NET 3.5 CAB from Microsoft or use DISM command (requires Windows installation media mounted as D:): Sometimes the installer fails to register COM libraries
dism /online /enable-feature /featurename:NetFX3 /source:D:\sources\sxs /all /limitaccess
Perform these steps in order. Start with the simplest (restarting) and move toward more technical solutions (registry editing).