What Are The Steps To Wipe Everything Off My Computer And Start Over And What Do I Need?

If you have an operating system on a disk such as Windows, just  place it into the drive and boot up your system. When it asks to format  your hard drive, select "yes". This will remove all files on your hard  drive and put the new operating system files onto your hard drive.  If you don't have an operating system disk, you'll need to get  a hold of one. While in DOS mode, you can type FORMAT C: (assuming your  hard drive still has the default drive letter "C:") to completely erase  your hard drive. But, without that operating system, you'll just have a  blank hard drive and won't be able to boot up your computer without a  boot disk (i.e. Operating system disk)

There are many ways to clear your hard disk drive, from the methods mentioned above to software that totally obliterates the data on the drive, by changing the scan head orientation position settings and thus making it impossible for the data to be read. However, these more drastic fashions of clearing the drive are not necessary under normal circumstances.
 Now if you are dead set on wiping and starting over, as opposed to trying to figure out what is wrong and fixing it, then the things you will need are:

1. Your installation disk for your operating system, whether it's Windows, Linux, or Billy Bob's Backwoods OS. Whichever operating system you intend to run, you'll need to have the appropriate disk, and the matching Registration Code, if the os you intend to use needs one (like Windows).
2. Before beginning the process, you should know what hardware you have in your computer (if you don't know, you can look on the website of the company that built your computer, or if it's not a corporate pre-built, you can usually go to your 'System Properties and see it there: Start -> Control Panel -> System -> Hardware -> Device Manager ... Then write down everything it says is mounted in your system). The reason to know this is that you will need to go to the websites of the companies that made the devices in the pc, and download the most up to date drivers you can get. Once you have them, burn them to a cd and set it aside for after you install the os.
3. You will need the install files for any and all programs you use on a regular basis, as well as any registration codes they will need as well. Otherwise you will not have those programs when you need them. (and don't include a bunch of stuff you don't use, that may well be why your system went down the tubes in the first place.)
4. Spare patience. During the installation of an operating system, and the drivers, and the programs, you will have to restart the computer not less than 6-8 times, and it will take a serious amount of time. Have patience, don't get frustrated (you'll be happier when it's done), and just stick with it. You'll be fine.
5. And lastly, make sure you have written down ALL the passwords you use on all the websites and programs you use, as well as backing up your favorites folder in your browser (there are plenty of sites that will explain how to do so), otherwise you will lose those sites you love to visit.

Good luck and have a great day.