The System Restore I am talking about is the one built into XP. It should
not remove any applications - at least nothing installed before the restore
point you apply and you are supposed to be able to "undo" a System Restore
Point if it you do not like what it does.
You certainly can use a different software firewall if that is all you need
and just forget about the Windows Firewall if you can not make it functional
though keep in mind another software firewall can be more complicated to
configure especially if you have outbound protection enabled as most of them
do by default.
There is a free tool called Dial a fix available at the link below. In it
tools section is an option to reinstall the Windows Firewall that may be
worth trying. Though you may want to try repairing Winsock and reset TCP/IP
first if the Dial a fix utility does not work.
http://www.softpedia.com/get/System/System-Miscellaneous/Dial-a-fix.shtml
Other fixes I would try would be to repair winsock and repair tcp/ip if you
have not tried that yet. Keep in mind that doing the below will usually set
a computers TCP/IP to be auto/DHCP even if the computer had static IP info.
So if you have a static IP on your computer be sure to document it first
before procedding. You can use the ipconfig /all command to view your
current IP configuration. If it shows DHCP enabled as NO then you have a
static IP.
Manual steps to recover from Winsock2 corruption
Windows XP with Service Pack 2 instructions [should also work with SP3]
To repair Winsock if you have Windows XP Service Pack 2 (SP2) installed,
type netsh winsock reset at the command prompt, and then press ENTER.
Note Restart the computer after you run this command
How to reset Internet Protocol (TCP/IP)
The reset command is available in the IP context of the NetShell utility.
Follow these steps to use the reset command to reset TCP/IP manually:
1.. To open a command prompt, click Start and then click Run. Copy and
paste (or type) the following command in the Open box and then press ENTER:
cmd
2.. At the command prompt, copy and paste (or type) the following command
and then press ENTER:
netsh int ip reset c:\resetlog.txt
Note If you do not want to specify a directory path for the log file, use
the following command:
netsh int ip reset resetlog.txt
3.. Reboot the computer
Steve