Until recently my operating system was XP where for the purpose of development and testing of php and zen cart I set up xampp that included apache http server and mercury mail server I also made changes to

C:\Windows\System32\drivers\etc\hosts

as follows:

127.0.0.1 www.zen.com # For browser access

127.0.0.1 mail.mercury.com # For email access

127.0.0.1 mercury.com # For mercury mail server

This allowed the use of www.zen.com in the address bar of my browser rather than 'localhost' and mail.mercury.com to access email via thunderbird. All was well.

Then I installed windows7, I made all the mods and again everything appeared to run as expected.Then I turned off my wireless modem causing all working local connections to fail. Localhost in the address bar still works but not www.zen.com and thunderbird 'cannot find mail.mercury.com'

Is there some way to overcome what ever is causing this.