To run version 8.1 effectively, your system should align with these legacy specifications:
Altera (now Intel) Quartus II 8.1 Web Edition is a legacy software suite used primarily by students and hobbyists to design for older Altera FPGA and CPLD families. Released around 2008, it provides a complete design environment for HDL analysis and synthesis timing analysis, and RTL diagram examination Key Features Comprehensive Design Flow: Altera Quartus II 8.1 Web Edition -Windows- free download
Unlike modern tools, Quartus II 8.1 Web Edition does not require internet activation. However, it requires a license file to enable the Web Edition features. To run version 8