How Do I Find Out If Someone Else Is Linked to My Computer?by Stephen Lilley
If someone is linked to your computer, it means that the two machines are on the same local area network. Typically this is done with the intention of sharing files between computers. However, it is possible to set up a local area network at the same time you're setting up a shared Internet connection and not even realize it. In the event that this occurs, you can find out if someone else is linked to your computer by opening a very specific folder.
Click "Start." After that, click "Computer."
Scroll down using the window on the left side of the "Computer" window. Click once on "Network."
Look over the folders you see onscreen. This will display a list of shared folders (if any are available) on the network. If there are any other computers linked into yours on the same network, the name of their computer will appear as an item in this folder. If no such items exist, nobody is linked into your computer on the same network.
Click "Start." Click "My Network Places," then "Entire Network."
Double-click the icon onscreen that reads "Microsoft Windows Network."
Double-click on the icon you see onscreen. This icon represents any network that your computer is connected to. Once you do this, all of the computers that are linked into your own will appear in the folder onscreen in the form of icons. If none of these icons are present, no computers are linked into yours.
- global computer network image by Michael Brown from Fotolia.com