HELP pc HARDDRIVE PROBLEM NEED HELP FAST!!!!?

Ok i am a computer wiz compared to alot of poeple but i dont know how to fix this i rescently rebooted (no restart more like formated) my computer.. and i knew i would probably loose my file ( though i had done it once before and kept all files) and i did well sorta... i discovered that the files i had before i rebooted were still taking up space, so i found some freeware to help me a recovery tool UNDO DElete i found the files but it is a trial and i cant do anything with it.....so the files are in USERDATA file under in my hardrive but its not accesible, so now i have a full harddrive and 70gigs of space is being filled with files i cant use PLEASE HELP I AM GOING INSANE TRYING TO FIND OUT HOW TO FIX THIS aANY help is GREATLY appreciated............ok so ididnt format i used a recovery application i found out but not normal one however that doesnt help me get my space back or understand y it hid the files THIS time not last and i dont have the cd