请问大侠,为什么将Trusted_Connection=true改为Trusted_Connection=false可以消除错误:"用户 'NT AUTHORITY\NETWORK SERVICE' 登录失败。"?

为什么将web.config中Trusted_Connection=true改为Trusted_Connection=false可以消除如下错误:
"用户 'NT AUTHORITY\NETWORK SERVICE' 登录失败。"

具体的如下:
change
<add key="ConnectionString" value="server=localhost;uid=sa;pwd=gofudan;Trusted_Connection=true;database=Store1" />
to
<add key="ConnectionString" value="server=localhost;uid=sa;pwd=gofudan;Trusted_Connection=false;database=Store1" />
to fix this error.

谢谢噢