hacks wont open in injector

when I go to add the hack.dll into the injector i get a box that in the top says select the library and inside saying You don't have permission to open this file... contact the file owner or administrator to obtain permission. its absolutely rediculous because it only happens with the hack (ex. the cham) not anything like the "d3d9.dll" type of file. i am the admin of the pc, i run as admin, im using vista 64bit. idk what is wrong. anyone else ever seen this b4??? and what can i don to fix?