How to configure Windows XP Firewall for network sharing

If you have confirmed that folders are shared properly but you still cannot connect, then the Windows firewall may be blocking the network. Launch Control Panel->Windows Firewall. Select the exceptions tab as shown in the screenshot.

If you are not using Windows Firewall but are using a third party product such as ZoneAlarm or Norton Internet Security then a similar exception will be necessary. Please try disabling your firewall temporarily to see if this is the problem.