The behavior of the node agent in WAS v6.1 ND not starting
automatically is by design. Use the following command from WAS's \bin
directory to add the process as a Windows Service. Then you can use
"net start" / "net stop" commands with the service name = "IBM
WebSphere Application Server V6.1 - nodeagent"

Here is the exact line command (split up so you can read it) which
worked for me. I have installed everything in E:\Program Files.

E:\Program Files\IBM\WebSphere\AppServer\bin>

WASService -add nodeagent -servername nodeagent
-profilePath "E:\Program Files\IBM\WebSphere\AppServer\profiles
-wasHome "E:\Program Files\IBM\WebSphere\AppServer"
-logfile "E:\Program Files\IBM\WebSphere\AppServer\profiles
-logRoot "E:\Program Files\IBM\\WebSphere\AppServer\profiles
-restart true
-startType automatic

The profile path is the profile where you actually find the
startNode.bat and stopNode.bat. No other profile will work. So look