For those that want to use the Pardiso solver you need to download the solver from the site specified : http://www.dhondt.de/calculix_2.20_4win.zip. The download will give you the following files:
ccx_dynamic.exe, ccx_static.exe, cgx_FREEGLUT.exe, cgx_STATIC.exe, glut64.dll, README_install and tetgen.exe.
Copy those files to the Solver folder in your PrePoMax directory.
ccx_dynamic.exe is the solver that uses the Pardiso solver. You activate it by going to the Tools/settings/ options in the menu and then changing ccx_static.exe to ccx_dynamic.exe
You will then have to download the following libraries and copy them to the solver folder of your PrePoMax installation:
libiomp5md.dll, mkl_avx2.2.dll, mkl_avx512.2.dll, mkl_core.2.dll, mkl_intel_thread.2.dll, and mkl_rt.2.dll.
You download those libraires from the intel site:
Get Intel® oneAPI Math Kernel Library
Once you have all those files in the solver folder, you can then chose to use the Pardiso solver for your model.
Cheers!