Everytime I goto a download website, find cute sims clothes then download it everytime I try it....?

Goes to my WIN archive where the file is stored.. normally with my other cusotm content I double click it and something from the sims says : would you like to install this to your sims 2 game file? but this time when I tried a whole bunch of gibberish popped up and the sims box won't come up.. HELP!