To understand why 2.7.1 is still searched for, a brief history helps:
Modern EDA suites are giants. They require high-end CPUs, dedicated GPUs, and gigabytes of RAM. Protel Advanced PCB 2.7, by contrast, was designed for Windows 95/98 and Windows NT. It is incredibly lightweight. For simple 2-layer boards or basic schematic capture, it runs instantaneously on modest hardware. This "bloat-free" efficiency appeals to those who value speed over features they won't use. Protel Advanced Pcb 2.7 1 Download
Protel Advanced PCB 2.7.1 Download: A Guide to Legacy PCB Design To understand why 2
While it is no longer sold, some versions may require original registration codes (e.g., 1007946 ). Protel 2.7.1 vs. Modern Tools (Altium Designer) It is incredibly lightweight
I can give you more specific advice on installation or alternative, free modern software.
If your goal is simply to design a basic PCB for a retro computer (e.g., a 6502 or Z80 project), used modern free tools are vastly superior.