If you have two or more computers located in your home or office, there are three compelling reasons to connect (network) them together:

1. To provide high-speed Internet access to all of your computers.
2. To avoid "data file synchronization" problems.  Which is a fancy way of saying that the information you're looking for is almost always on one of the other computers.  By connecting the computers together you will be able to access information on any computer in the network from any other computer in the network. 
3. To share peripherals such as printers and scanners

Once that decision has been made, I can help you purchase the necessary networking equipment, run the cables (for wired) or set up the proper safety protocols (for wireless), as well as make any necessary settings to Windows and your other software to insure that your network will be seamless.