Professional software protection system without hardware keys. PC Guard for Win 16 offers fully automatic protection of the Windows 3.x 16-bit executable files. With PC Guard for Win16 you can protect unlimited number of your programs with no additional investments! PC Guard for Win16 can link protected program with specific motherboard (BIOS checksum) and (or) with protected program disk position. Executable file structure is changed, starting segment can be encrypted and many anti-debugging techniques are used against reverse engineering.