Backslashes should be escaped, for example: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w3svc\parameters\Script Map] ".php"="c:\\php\\sapi\\php4isapi.dll "Now merge this registery file into your system; you may do this by double-clicking it.
Par exemple: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w3svc\parameters\Script Map] ".php"="C:\\PHP\\sapi\\php4isapi.dll "