Remote machine is unaccessible from the Agents Management Console

The problem may occur due to several reasons:

Reason 1
You didn't enter or entered incorrect admin login or password
Reason 2
Remote machine works under Home Edition of Windows OS. Unfortunately, in this case the problem can't be solved.
Reason 3
Remote machine works under Office Edition of Windows(for example, WinXP Prof), but in the Windows Explorer in the "Folder Settings" dialog, the "Use simple file and folder sharing" option in enabled. Disable this option and try again.