A: A single commercial license of CATIA V5 (Mechanical Design bundle) costs between $10,000 and $15,000 USD upfront, plus annual maintenance (~$2,000). Academic licenses are ~$100/year. There are no cheap "home user" licenses.
Before downloading CATIA V5 R19, ensure your computer meets the minimum system requirements: catia v5 r19 download
Setup.exe as Administrator.Assuming you have secured a legal license (student, trial, or commercial), here is the legitimate installation process. Note that you will NOT get "V5 R19" but "V5-6R202x" or 3DEXPERIENCE. A: A single commercial license of CATIA V5