Blocked ports, help with troubleshooting please!

[rnott]

I have a problem where some software blocks ports (110 and 25). My
system is
Windows XP, Service Pack 2, with all Microsoft patches up-to-date.
Antivirus software and firewall are switched OFF. Network connection/
connectivity is fine and otherwise fully functional.

When I switch to "safe mode", the ports open and the problem
disappears (but of course I shouldn't usually work in safe mode).

Is there a systematic way to find out what ports are blocked and what
is blocking them?

Thanks,
Wolfgang,
CA

A bit more detail on the background of my question:
=======================================
In my specific case Outlook Express suddenly started reporting that it
couldn't connect to my ISP's POP and SMTP servers (ports 110 and 25)
anymore. I disabled the Norten Antivirus, but NO success.

I looked at the Task Manager process list and at the running services,
but this is confusing with the many, many processes running and no
indication of what may they do to ports.

Then I re-started the XP system in Safe Mode, and Outlook Express
sending/receiving works FINE, indicating that in Safe Mode the
offending software, whatever blocks ports 110 and 25, is disabled.

So, how do you find out which software is the offender, blocking ports
110-25 in normal mode. Do you know a more systematic way of doing
this, rather than the guess work of disabling one after the other of
tens of processes?

 

[Guest]

Hi Wolfgang,

seems that you have installed a personal Firewall and misconfigured it.
My guess is that you have not installed Norton Antivirus, but Norton
Internet Security. There is a firewall included.
If this is right, disable the Norton firewall part and not the Antivirus.

Greetings
Florian

 

[rnott]

Thanks Florian,

As far As I can tell, I have disabled ALL Norton services in the
services panel, and indeed I don't see any Norton processes on the
task list. If a Norton service or task is still running/hiding
somewhere, do you have any clues how to identify it, so I can kill it?

Thanks

PS: Also, I'm still looking for a SYSTEMATIC way to identify blocked
ports, rather than the trial-and-error switching off this and that and
seeing if that makes the original application work.

 

[Strings3002]

Have you tried using system restore? I had the same problem awhile
back. System restore worked at the time. A friends computer had a
similar problem as well and system restore did NOT work! His access to
the restore function was completely blocked. In his case he had a
Trojan horse virus from sharing MP3's. It had quietly turned off his
Norton anti virus. It had also disabled the WinXP firewall and blocked
the ports110 and 25. We assumed it did this to keep the ports to
itself for it's own use. Panda active scan was able to remove it at
the time. We then used system restore to go back to before the virus.
This last step fixed the connectivity issues. Then, after testing
again that connectivity was restored. We had to clear out the old
restore points and make a new one. So, you may wish to use an on-line
Anti-Virus just to be sure.
Good luck!