Security Essentials is simple solution against viruses, spyware from Microsoft.
It is usuful for, for example, test environments with virtual machine(Virtual PC or Virtual Server). We often manage some test environments in development machine (Sometimes they cover OS variation, others they cover requirement variation).
However, they are rarely connected to web directly. So definitions update fails.
We can update via proxy.
Here is a message for update fail.
This concept is very simple: We just can use IE proxy settings.
1Set the IE LAN settings to use proxy server.
2Execute following command with [Administrator command prompt].
01netsh winhttp import proxy source=ie