As you have not mentioned as to which Operating System you want to install, I am providing the below mentioned link which has steps to format the hard drive in Windows XP Operating System interface and using a Windows XP Disc:
There are other methods of formatting the Hard Disk, such as "FDISK" utility.
There are several different steps during installation that vary from one Operating System to another. So it must be clear beforehand as to which Operating System you want to install. So that I can assist you further, please reply with the Operating System you want to install in the computer.
Also, necessary software varies for different users depending on the needs. For example, for an office user "Microsoft Office" is a must have while a multimedia expert should have "Adobe Photoshop".