You can use several applications to repair a computer remotely, including teamviewer, GoToMyPC and LogMeIn. You can set up virtual network computing on both computers to repair one remotely. If both devices use Windows, you can use Windows remote desktop assistance to repair the computer remotely.
Teamviewer is a free, cross-platform remote desktop sharing application that allows you to connect to another person's computer. It works on Linux, Mac and Windows devices. The person who needs his computer repaired should have the teamviewer quicksupport application. The application gives him a session ID and a password, which he gives you. This allows you to access his computer remotely to repair it.
LogMeIn is a powerful tool that allows you to remotely access a person's computer to repair it. You can repair the computer while the owner sits in front of it or in the background without disrupting the owner's work. It also has a wake-on-LAN feature that allows you to remotely wake up another person's computer and repair it when you are free.
GoToMyPC is not free, and it is a browser-based solution. The other person installs the GoToMyPC client on his computer, and you access the computer and repair it through a Web browser on any computer. If you have access to the other person's computer, you can set up virtual network computing. Set up port forwarding on his router, change the default VNC port, and secure this connection with a user name and password.
Windows users can use the Windows remote desktop assistance feature. The person who needs help can access the feature and click on Invite Someone You Trust to Help You. That person can then select Easy Connect to get the password to give to you.