To share a file or folder with your fellow computer users, move the file into your Shared Documents folder, which lives in your My Computer window. (You must move or copy a file into the Shared Documents folder; shortcuts don't always work.)
After you place your file or folder into your Shared Documents folder, it appears in the Shared Documents folder of everybody else using your computer.
Administrators can share folders without having to move them into the Shared Documents folder. The trick is to follow these steps:

1. Right-click on a folder you'd like to share and choose Sharing and Security from the pop-up menu.
Open My Computer and right-click on the folder you'd like to share. When the menu appears, select Sharing and Security. A window appears, showing the Properties for that folder. It opens to the Sharing tab.
Right-click on a folder and choose Sharing and Security to share the folder on the network.

2. Click the box marked Share This Folder on the Network.
A check mark in that box lets everybody peek at, grab, steal, change, or delete any of the files in that folder. To let visitors look inside the files but not change them, remove the check mark from the box marked Allow Network Users to Change My Files.
3. Click OK.
Now that particular folder and all its contents are available for everybody on the network to share.
Sharing a lot of folders isn't a good idea because it gives network visitors too much control over your computer. Even if you trust people, they might accidentally mess something up. To be safe, only share files by placing them in the Shared Document folder.

Inside Shared Documents live two more folders, Shared Music and Shared Pictures. Those two folders are also available to any user. So, if you want to share documents with any user of your computer, store them in the Shared Documents folder. When you make MP3s from your CDs, store them in the Shared Music folder, too, so that everybody can enjoy them.