Offer Remote Assistance Error on laptops

[Guest]

I have a number of Dell Latitude D600 laptops running Windows XP Pro with
both SP1 and SP2. I am unable to Offer Remote Assistance to any of the
laptops, I receive the error "Remote server machine does not exist or is
unavailable" as soon as I try to connect - there is no problem offering
remote assistance to desktops!

I have a group policy set up to enable Remote Assistance and the following
exceptions for SP2 firewall blocks:
%systemroot%\system32\sessmgr.exe
%systemroot%\pchealth\helptctr\binaries\helpsvc.exe
Port - TCP 135
Remote Desktop - port 3389

I have searched Microsoft and other forums - is there something else that I
am missing?

Thanks in advance for any help!

2nd posting - Sorry

 

[Brian Steele]

You might want to check your group policy settings for firewall program
exceptions. The following are supposed to work (according to the help
information):

%windir%\system32\sessmgr.exe
%windir%\pchealth\helpctr\binaries\helpsvc.exe
%windir%\pchealth\helpctr\binaries\helpctr.exe


I'm however, getting the same error when trying to connect to both desktops
and laptops on my LAN, even with the above-mentioned settings!

The event log also reports the following error:

DCOM was unable to communicate with the computer (computername) using
any of the configured protocols.


A search on the MS Support site turned up nothing to help resolve the
problem, apart from a suggestion to check a certain registry setting, which
turned out to be set correctly on the PCs in question.

Interestingly enough, if a user firsts requests assistance, then Remote
Assistance works. The problem happens when an administrator tries to offer
Remote Assistance, instead of accepting an invitation from the user.

Regards,
Brian