Are theyon the same network?Do you know the IP address?What operating system are both computers using?
Is the computer you want to work on operational? Are you simply wanting to use another computer to get around a location issue? If so, a remote access program such as MyPC, TeamViewer – or VNC and Remote Desktop (RDP) are good if you are on a network. If the secondary computer is not operational, you could insert the hard drive into your own computer, and access it that way for work.