(at any mod, sorry, but it could be legit, i myself downloaded some games that i own, but only have as way scratched discs, lets assume the same here, sorry if im doing something wrong)
First off, read the above, note that we will not in any way help you with games you do not own, WAREZ ARE BAD!
That being sayd and me being the nice and open minded guy that i am lets assume the above (about you owning the game) applys;
.7z is a common format for downloads (lol) its similar to a zip or rar file, to my knowledge 'winrar' should open it, if it doesnt; google '7zip' and get that app, open the file and see whats inside, if you see like a 'system.cnf' file its the actual game, unpack the .7z and make a iso from the files with isobuster/nero/clonecd or some similair app & copy that to iso's directory, it could also happen that theres an actual iso or similair in the 7z, then just copy that to iso's directory.
now lets switch subjects since im hearing thin ice crackle below me
Im a FpseCE supporter!