You will have to give more information: How big is your new hard drive? Are the jumpers on it well set? By default most manufactures will sell them CS (cable select); but if the hard drive you have now is set Main or primary then you will have to change the jumper on your new hard drive to slave; or change your existing hard drive to CS.
If you have service pack 2 you can install just about any size hard disk, but if you don't have SP2 then you will be limited to ~ 127 Gig.
To format it you will have to go to your control panel:: administrative tools>computer management>storage>disk management ,,,once there you should be able to find your way around, its' all there...action, rescan disk....tools format using NTFS.