By Al Fasoldt
Copyright © 1998, The Syracuse Newspapers
Last week I explained how easily I was able to cruise through the files and folders of another computer that was connected to the Internet. Both PCs were running Windows 98, and the PC I connected to was using Microsoft's File and Print Sharing.
The owner of the other PC had not intended to give me or anyone else access to his computer, but I didn't need any super-sleuth techniques to browse through his PC's files and folders, and it was even a simple matter to tell my PC to use his PC's printer.
This came about because of a little-understood function in modern versions of Windows called File and Print Sharing. This method of letting other computers get at your files and your printer wasn't supposed to be an Internet-related function—Microsoft designed File and Print Sharing for home and office networks, long before the Internet became a two-click destination. But it's now one of the major reasons PCs are vulnerable to intrusions across the Internet.
This week I'll tell you how you can protect your Windows 95 or Windows 98 PC from that kind of vulnerability.
File and Print Sharing is a function of Microsoft Networking. If your PC is not connected to an office or home network, chances are you don't have File and Print Sharing set up, and you probably don't need to worry. But please note: Anyone who uses your PC—your 14-year-old, for example—can add File and Print Sharing even if you are not connected to a network. So follow the instructions I'm about to give to see if it is installed.
To see if File and Print Sharing is installed, click your right (or alternate) mouse button on the Network Neighborhood icon. Click Properties (with either mouse button). The Network properties window should open. If you have no Internet software installed, no network software in use and no File and Print Sharing installed, you may not see anything—or you may see a message from Windows asking if you want to install networking software. (If you see that, choose "No" or "Cancel.")
If you do see items listed in the Network properties window, you have at least some networking software installed. (Remember, you don't need to be connected to a home or office network. Your Internet-connection software is part of the networking system.) Look in the lower part of that window. You'll see a "File and Print Sharing" button. Click once on that button.
If Microsoft's File and Print Sharing software is not installed, you'll be asked if you want to install it. (Don't, unless you know what you're doing.) If it is installed, the "File and Print Sharing" options window will open. It shows both choices (sharing files and sharing printers). Checkboxes at the left show whether each feature is turned on. File sharing is the option that is most dangerous on the Internet. Printer sharing doesn't leave your files and folders vulnerable, but it's a dumb idea across the Internet because spooled printer files can be gigantic; printing them to a remote printer could take hours.
You can turn off File and Print Sharing completely using the checkboxes—a good choice if the only network you connect to is the Internet. If your PC is on a home or office network, and you need to share your PC's files and its printer, click the "Access Control" tab at the top of the window and see what's already set up. If you have a Windows peer-to-peer network, "Share level access control" is the only one possible. If you have a network that uses a real server, you should be able to choose "User-level access control." (Most of you won't have that option.)
Next week we'll finish this series by seeing how you can continue to use File and Print Sharing without endangering your files.