i used to use HCE all the time, then one time i loaded it and it stayed at the loading screen... and sat there... i tried in game reset and nothing happened so i had to manually restart it. i never edited any of the files, but i figured oh well, and i deleted it and re-downloaded it from xbins, ftp'd it back to my xbox, and once again it still didnt load. do i need to load it BEFORE starting Halo, then return to it after copying a map to the cache? or the other way around, will it make a difference? should i delete halo then re-copy it to my hdd?

Delete it all from your Xbox HDD, clear your cache, and delete any savefiles that belonged to the game. Then reinstall everything that you had.