unable to login in messanger error:-81000306

I am using Windows Vista and installed IM 8.5 but when i tried to logon its
give the error number 81000306. your firewall setting is blocking i disabled
the windows firewall then also it didn't loggod.

i tried to logon through web im it logged on successfully and then
simaltanously i tried to logon the local system. it logged out from the web
by giving the message that you had logged on at some other computer. but the
logging at my local system failed by giving the same 81000306 error.

Kindly help me because it is really urgent for me.

thanks in advance to all.

Shiva