by default, you can find the necessary files on community repositories:
The SG3524 is a staple for designing inverters, switching regulators, and DC-to-DC converters. While Labcenter Electronics periodically updates its database, most users rely on community-contributed libraries from the following sources: sg3524 proteus library download
The SG3524 model has floating pins or missing power connections. Fix: by default, you can find the necessary files
If you cannot find a dedicated library file, you can import a SPICE model (often available from manufacturers like TI or ST): how to create aSG3524 in proteus 7 professional sg3524 proteus library download