i reformatted my computer and my hard drive is listed as (I:) is there any way to change this?
If you installed Windows on drive I:, then you can't simply change the drive letter to C: and hope that it works. Fortunately Windows is smart enough not to let you change it for a system or boot disk.
If you installed on drive C: and the drive letter changed after the initial installation, then follow this procedure: http://support.microsoft.com/?scid=kb%3Ben-us%3B223188&x=21&y=14.
Make sure that you fully understand what issue this procedure resolves.