Windows 7 - Problems with windows live messenger

Hi i am having a trouble with my messenger
After the fresh install of Windows 7 i installed the messenger and everything worked fine. But after few days it stopped working saying that messenger can not connect to the internet. I checked my firewall i scanned my system but nothing helped. I thought that problem might be with windows its self so i wiped everything of and done another fresh install of Windows 7. After that messenger worked fine again well for few days that is and now i have a same problem as b4. Any suggestions will be appreciated.
Many thanks 4 yr replies in advance...