The clipboard on a computer is not a specific software that can be accessed; it is a tool used by the computer to save cut or copied information for pasting to another location. As soon as a new item is copied to the clipboard, whatever content was there before is permanently overwritten.
Older Windows operating systems (2000 and XP) have a clipboard viewer. The file is named "clipbrd.exe" and is located in the System32 folder, which is located in the Winnt or Windows folder. Another way to access the file in these older operating systems by using the Start menu, choosing Run, typing in "clipbrd" and pressing "Enter."