While migrating from exchange 2003 to exchange 2010 you see mail queus building up between the exchange 2010 server send mail to exchange 2003. The error yuo see is Exchange 2010 Queue 451 4.4.0 Primary target IP address responded with: “451 5.7.3 Cannot achieve Exchange Server authentication. Solution here.
How to renew your expired exchange 2007 certificate.A guide on How To Remove An Expired Exchange 2007 Certificate and Create A New Certificate. This needs to be done every so often when your exchange certificates expire.
If you have a nero NRG file and you want to burn it bont dont have a copy of nero then you need to convert it to ISO. Here is a free guide ona utility on how to convert and burn Nero NRG files to ISO files.