Nestopia is a free and portable Nintendo Entertainment System (NES/Famicom) emulator. It allows you to play and emulate ROM files from the NES system while enjoying past favorites from the 80s and early 90s.
Playing NES Roms with this emulator is a piece of cake and the ability of this application to properly replicate Nintendo games is excellent. That goes both for sound and video.
Version 1.40 is a freeware program which does not have restrictions and it's free so it doesn't cost anything.
Virus and Malware Tests: The program has been tested with several antivirus applications and has tested clean of viruses, malware or trojans.