things not opening...?

ok.. so some files that i download, like handbrake, utorrent, transmission, bittorrent, etc all download well and fine..
i get a little icon connected to the thing i downloaded...
buuuutttt it won;t open.. i click it, double click it, double click again.. restart my computer. nothing i try works it just sits there... doesnt open..

does this happen with any one else??

i also downloaded something called MacOSX combo something or other.. the apple website said it might fix the problem.. but it's still doing nothing...

What file extension do they have, if any? .zip, .sit, .rar?

how would i check thatt???

do "get info" on the file that is downloaded.

If you right click ( control click) a file or application, a tab should open up revealing "get info".