As of about 7pm last night I got randomly signed out of MSN Messenger. However much I tried to sign back in, it said nah bob I think I'm happy like this ty very much and each time, within 3 seconds, gave me the message "Sorry, we were unable to sign you in" etc etc.

The computer is connected to the internet through a router upstairs, and the other computer on the network can get into MSN fine. Nothing else is wrong right now (except microsoft downloads on msdnaa not working but hmmph leave that).

I tried the troubleshooter, that's fine. Checked all the settings, that's fine, tried a different port on the router, same thing. Left it over night, same thing. Tried reinstalling MSN, same thing, tried making sure the permissions were ok on my firewall, same thing, tried restarting! same thing . It's just really annoying because I need to be on MSN, and I just can't get on! It's more annoying that the other computer has no problems but I can't use that because he needs it as much.

Help >.<

It could be MSN servers having trouble (if it was working fine before and nothing was changed in the firewall/network settings), but if it lasts long you can try the following:
Go to ....
start > run > type: regsvr32 softpub.dll <enter>
start > run > type: regsvr32 initpki.dll <enter>
start > run > type: regsvr32 mssip32.dll <enter>

If you still can't login after that, look at the first two posts in:
Possible solutions for "We were unable to sign you in to .NET Messenger"

If you can't reach/view any microsoft site, the first command oughta fix that aswell (along with IE settings ofcourse, more about that in the thread i linked to)

Edit: Never mind.

Told Messenger to forget the account and retyped it (and the password was already right!!! lol) and it worked.

Hate how often MSN messes up -__-