How do you install a new hard drive for a Dell Inspiron 1525?

I bought a new hard drive for my laptop and it is not working. It is a 160gb, when i run the tests, it keeps saying an error message, and wont like let me login, it goes from the dell logo to the error massageHow do you install a new hard drive for a Dell Inspiron 1525?did you install an operating system on it ?