msn messenger - hotmail - sign in issue

A relatively minor albeit frustrating issue.

 

I have just been sent an XPS M170 laptop to replace a previously faulty machine. I've installed MSN Messenger 7.5.

 

If I try and open Hotmail through the mail notifier link, it constantly tells me my sign in information is incorrect and would I please enter my username and password again.

 

I have reinstalled MSN and IE and cross checked all the settings of these applications with another machine where the log in works perfectly. It seems this problem only arises on the XPS laptop as it works fine with many of the other systems around the network.

 

Some advice would be appreciated.

 

Lee.