First, please make sure that you have installed IP Blocker correctly. You need to log on Windows as a real administrator and run from there.
If IP Blocker was correctly installed, then the problem may be caused by not allowing unsigned driver software. The following image shows the configuration of driver signing options in Windows XP. Please select "Ignore" or "Warn", do not choose "block". The "Driver Signing Options" dialog can be showed in Windows XP by following steps:
1. Right click "My Computer" icon and select "Properties" menu item.
2. "System Properties" window shows and select "Hardware" tab.
3. Click "Driver Signing" button.
This is becasue the current user does not have the privilege to write file on C:\Program Files(x86)\IP Blocker Firewall\ folder. You may change the privilege or reinstall this application on disk D:\ to avoid this error.
IP Blocker can not be successfully uninstalled on windows operating system sometimes. In this case, you have to kill the uninstalling program manually by Windows task manager, and then try uninstalling program again. IP Blocker will be successfully removed on the second try.
If you click the "Block" button and set the blocking rule to block the "OTHER" protocol, you will not connect to the Internet correctly.