If you have a legal license file (license.dat) from 2008 but lost the installation disk, you are in a gray area.
While Comsol Multiphysics 3.5a was a masterpiece of engineering simulation, its time has passed. Pursuing a "free download" of this specific legacy version is a dangerous game. Comsol Multiphysics 3.5a Free Download
. Check with your institution's IT or engineering department for availability. COMSOL Client free Windows client If you have a legal license file (license