The Simple File Sharing feature of Windows XP is not supported by Management Utilities, and must be disabled on all XP systems. To disable this feature, choose My Computer from the Start menu or the Windows XP desktop. Go to Tools - Folder Options. Click the View tab and find "Use Simple File Sharing (Recommended)" in the list of advanced settings. It should be at or near the bottom of the list. If the feature is enabled, click to clear the checkbox. Click OK to close the Folder Options dialog.
To configure the Windows firewall, choose Control Panel from the Start menu. In Control Panel, go to Windows Firewall. The Windows Firewall dialog will be displayed. If the firewall is enabled, you will need to add exceptions. Click the Exceptions tab. Check the box for File and Printer Sharing. Click OK to close the Windows Firewall dialog.