Error: "'net' is not recognized as an internal or external command, operable program or batch file"

Try looking for a file called net.exe in C:\WINDOWS\system32\

If it is there then try using an explicit path to the file in your script.

E.g.:

C:\WINDOWS\system32\net.exe start iisadmin

Sounds like your 'path' environmental variable is getting stomped on somewhere. The fix is to do a direct call to it like has been suggested above.

Yep, seen it more than once. Try using the full path and name to net.exe.