File type .7z (Help needed)

I have downloaded many roms with the file type as .7zThis file type is in SNES and 64 games for emulators but it doesn't work on both.I'll give you an example:"I tried downloading Tetrisphere for the 64, (File type is 7z) but when I tried it on Project64, it didn't work. The emulator tells me that the file is either corrupted, or is not supported with this rom.anyone know how to use .7z for roms?????

.7z files are 7zip file arcchives, you must extract them first using the latest version of winrar. Incidentally there is a winrar tutorial here :)

you could also get jzip. it works with just about any zip file archive.its also free.here's the site. http://www.jzip.com

7zip is the original program for 7z files, it is also free and capable of opening rar files.