You may need to uninstall and re-install Windows Firewall because of the following reasons:
a) A third-party firewall has been installed and the two firewalls are conflicting with each other.
b) Windows Firewall is corrupt, and to fix the problem, it needs to be removed and reinstalled.
How to uninstall Window Firewall
The uninstalling process consists of:
– Disabling the firewall.
– Stopping the firewall.
– Removing all firewall files and registry entry
How to disable and stop the Firewall:
1) Click on Start menu, and select Control Panel.
2) Select Administrative Tools
3) Double-click Services option
5) In Services console, find and right-click Windows Firewall/Internet Connection Sharing (ICS)
6) Select Properties
7) Select Disabled from the Startup type list
8) Click Stop
9) Select Apply to confirm changes.
10) Click OK to exit the dialog box. This completes the process of stopping and disabling Windows Firewall Service.
Removing all Windows firewall files and registry entries
On Windows XP desktop, open a “Command Prompt” also referred to as “DOS Prompt”
11) Click on Start, then Run
12) Type cmd, then press Ok
13) The command prompt window will now.
14) Type the following command in full in the line indicated by the arrow above (Step – 13), and press Enter on your keyboard.
sc delete SharedAccess
15) Wait for about 10 seconds for the command to complete. The command removes all files and the registry entries of the firewall service.
How to reinstall the Windows Firewall Service
16) Open another command prompt, or use the one already opened in the preceding steps.
17) Type the following command in full in the command prompt, and hit the Enter key on your keyboard.
rundll32 setupapi,InstallHinfSection Ndi-Steelhead 132 netrass.inf
18) Wait for about 10 seconds for the command to complete.
19) Next, to reset Windows Firewall, type the following command in full in the command prompt, and hit the Enter key on your keyboard.
netsh firewall reset
20) Close the Command Prompt, and open the Control Panel as described in step 1.
21) Double-click the Windows Firewall option.
22) Click Yes when prompted by a message asking you if you want to start the Windows Firewall/Internet Connection sharing (ICS) service.
This should fix your Windows Firewall Problem, but if it doesn’t, you may try performing a System Restore, or re-installing the version of Windows Service Pack problem on your computer.