Our msm messenger would not let us sign in.  We received error
code0x81000370 and our email tech person walked me through all the
solutions, checking www.pasport, SSl2.0 and SSL3.0, etc.  Now we then
still couln't log in and then removed msn completely--then down loaded
it again.  Now we don't get that error message--but "unable to read
URL from host g.msn.com:80 connection reset by peer".  Please help us
figure this out.  My son had signed into msn messenger at various
other computers so we know his log in and password are valid.

There maight couple of possiable causes and solutions.
but try this one first : Click Start, then Run, and enter the
following: regsvr32 softpub.dll - then click OK"

if this doesn't work try the following

1.  The date on your computer needs to be set properly -- double click
the clock verify that
the time and date are set.

2.  Clear your IE cache and cookies -- open Internet Explorer, click
the Tools menu, then
Internet Options, then click the Delete Files button, and when that's
complete click the
Delete Cookies button.

3.  Check your IE Security settings -- open Internet Explorer, click
the Tools menu, then
Internet Options, then Advanced tab, scroll to the Security section,
and verify that "Check
for server certificate revocation" is unchecked.  Also verify that
'Use SSL 2.0' and Use SSL
3.0' is checked, then click OK.

http://www.experts-exchange.com/Networking/Q_20825957.html

It may be a firewall issue not allowing the new program to access the internet.

here you will find a list of the ports msn messenger is using.

http://www.bandicoot.nl/msn.html 

probably you set up your firewall or using a proxy to block all outgoing messages.

Check if it is blocked everything but 25, 110 (for mail in and out) 80
(for web and MSN traffic) and 443 (SSL which MSN uses to sign on). If
you block two IP addresses (65.54.179.198 and 65.54.183.198) then MSN
can't get through.

So you should be able to get through if you have 80 open, and 443 open
to at least these two IP addresses.

I hope it helps.
Phossil

check to ensure that your hosts file has not been modified by spyware or a virus.

c:\windows\system32\drivers\etc\hosts is the standard location in
winxp.  If you have no other uses for it (if you dont know then you
probably dont) then remove everything except for the following line

127.0.0.1   localhost (put a tab between those two)

Any other lines may be the cause of problems with MSN, norton, etc