I bought a new computer in January, and had Windows 7 installed on it. All elements of Windows Live Essentials worked perfectly.  

Recently, the hard drive failed, and had to be replaced.  Once again, Windows 7 has been installed – but this time, Windows Live Mail doesn’t work.  The error message says it cannot be installed because “msmail.dll cannot be loaded”.

The technician has given me Mozilla Thunderbird as a replacement, but it doesn’t work for me.  How can I get Windows 7’s Live Mail back?