More details r required ! OS is the most important and if possible mention the exact error no or message. If u r using Linux OS then u do the 11g zip files as when it comes to install…. please make sure unzip all the zip files into the same directory !
For eg. crate a folder / directory like database and copy those zip files in the same then make it unzip the zip files into the same directory / folder.
If it is windows OS, then most probably it is an error of Environment Variables > Path related. Once again I am requesting u please provide more details which help to resolve ur Q