Question : Server shutdown unexpected with different Reason Code

The client has a Windows 2003 R2 with SP2. Recently, the server has been shutdown unexpected with different Reason Code: 0x806000c, 0x8000005 and 0x805000f. He doesnt remember any thing change. The Event Viewer doesnt have other events when that happens. How do you troubleshoot this problem?

Answer : Server shutdown unexpected with different Reason Code

do you have a memory.dmp  on minidump.dmp

if yes  :    install "debbuging tools for windows"
at  http://www.microsoft.com/whdc/devtools/debugging/installx86.mspx

do file, symbol path
enter:    SRV*c:\websymbols*http://msdl.microsoft.com/download/symbols

and file, open crash dump

What it said?