In Microsoft Windows, enabling file and print sharing also allows files to be shared via the Internet. This is true regardless of which kind of Internet connection you use and, in most cases, this is probably not what you intended. This ability to share files can be used to infect your computer with a virus or look at the files on your computer. So, unless you really need this ability, make sure you turn off file and print sharing. If you must have file and print sharing enabled configuring your computer to require the use of a password is highly recommended and will offer good security, but there are also other steps you should take to secure your computer. Note: These directions should only be used by experienced computer users. This information should not to be construed as an attempt to provide legal, security, or other such professional advice.

Following are instructions for disabling file and print sharing on Windows 95/98/ME systems

1. Click Start->Settings->Control Panel
2. Click the Configuration tab
3. Click the File and Print Sharing button
4. Make sure the checkboxes for "I want to be able to give others access to my files" and "I want to be able to allow others to print from my printers" are not checked
5. Click OK button in that dialog box
6. Click the OK button in the Network control panel
7. If you are prompted to do so, restart your computer

If you must have file and print sharing turned on in Windows 95/98/ME, you should disable the TCP/IP binding for this service:

1. If you have file and print sharing turned on in Windows 95/98/ME Click-> Start -> Settings ->Control Panel -> Network.
2. Click TCP/IP->Ethernet Adapter, click Properties, and then click the Bindings tab.
3. Click to clear the File and Printer Sharing check box, click OK, and then click OK again.
4. Restart your computer.

Follow Microsoft's detailed "how to" on the web at http://support.microsoft.com/support/kb/articles/q199/3/46.asp.

Following are instructions for disabling file and print sharing on Windows NT

1. Click Start->Settings->Control Panel
2. Double-click the Network control panel
3. Click the Bindings tab
4. Highlight Server
5. Click Disable
6. Click OK

If you are sharing files on Windows NT, you should follow the following guide to NT security on the web at http://support.microsoft.com/support/kb/articles/q164/8/82.asp. You should first disable the TCP/IP binding for NetBIOS as follows:

1. Open the Network control panel (Start -> Settings -> Control Panel -> Network).
2. In the Network dialog box, click the Bindings tab, select the NetBIOS Protocol, and then click on the TCP/IP binding.
3. Click the Disable button to disable TCP/IP for NetBIOS.
4. Click OK, then click OK again.

Then you should disable the IP Forwarding feature as follows:

1. Open the Network control panel.
2. In the Network dialog box, click the Protocols tab, select TCP/IP Protocol, and then click Properties.
3. In the Microsoft TCP/IP Properties dialog box, click Routing.
4. Make sure the check box for Enable IP Forwarding is cleared.
5. Click OK, then click OK again.

Following are instructions for disabling file and print sharing on Windows 2000/XP

1. Click Start->Settings->Control Panel
2. Double-click "Network and Dial-up Connections"
3. Right-click "Local Area Connections" and select Properties
4. Uncheck "File and Printer Sharing for Microsoft Networks"

Follow these instructions if you need file and folder sharing enabled on Windows 2000 Professional/XP.

1. Click Start->Settings->Control Panel
2. (On Windows 2000 only, double-click "Administrative Tools")
3. Double-click the "Services" icon
4. On the right pane, scroll down and double-click on the "Server" icon
5. After "Startup Type" in the middle of the window, select "Automatic"
6. Click the "OK" button
7. Restart your computer
Sharing will be enabled after restart. You must now enable sharing for the individual resources you wish to share

On Windows NT and 2000 computers, if you don't assign a password to the Administrator and other privileged accounts your entire hard drive will be shared to the network. These operating systems create hidden shares of the entire hard drive which are available to privileged accounts. If those accounts have no password, anyone can access the share. To set a password on these accounts:

On Windows NT systems:
1. Click Start->Start->Programs>Administrative Tools->User Manager
2. Double-click the Administrator entry and set a strong password...
3. Do not forget the password

On Windows 2000 systems:
1. Click Start->Settings->Control Panel->Administrative Tools->Computer Management
2. Click Local Users and Groups
3. Click the expanding check box to the left of Local Users and Groups
4. Right-click the Administrator user entry and select Set Password
5. Set a strong password
6. Do not forget the password

For more information check your operating system and your other program help files to learn how to disable file sharing.

Macintosh users who rely on Mac OS 8.6 or below cannot share files over the Internet using the standard file and print sharing features of the cable modem. The reason for this is that these versions of the Mac OS can only use AppleTalk for file sharing, a protocol that the cable modem cannot handle.

Mac OS 8.5 and above does offer a form of file sharing that can operate over the Internet: Personal Web Sharing. If you are using Personal Web Sharing, you should ensure that this service is password protected and that you are only sharing the files you wish to have read or modified by other computer users via the Internet. Because you must manually enable this service, disable read-only access, and select which files you wish to share, it is unlikely that this service will present a security hole.

Mac OS 9.0 introduced the ability to share files and printers via the Internet using the TCP/IP protocol. While the TCP/IP option is disabled by default, you should ensure that file and print sharing on the Macintosh is password protected and that you are only sharing the files of your choice if you enabled the TCP/IP.