The /emssettings option sets the global Emergency Management Services (EMS) settings for the computer. To enable or disable EMS, use the /ems option. The /emssettings option does not enable or disable EMS for any boot entry.
bcdedit /emssettings [ BIOS ] | [ EMSPORT: port | [EMSBAUDRATE: baudrate] ]
To properly enable EMS console redirection after Windows is installed, Windows needs to know the port and transmission rate that the computer uses for out-of-band communication. Windows uses these same settings for EMS console redirection.
On computers with BIOS firmware and an ACPI Serial Port Console Redirection (SPCR) table, Windows can find the out-of-band settings established in the BIOS by reading entries in the SPCR table. On these systems, you can use the BIOS parameter to direct Windows to look in the SPCR table for the port settings, or you can use the emsport:port and emsbaudrate:baudrate parameters to override the settings in the SPCR table.
On computers that have BIOS firmware, but do not have an SPCR table, use BCDEdit and the /emssettings command with the emsport:port parameter to specify the port and with the emsbaudrate:baudrate parameter to specify the transmission rate.
On all systems, use the BCDEdit /ems command and specify the boot entry to enable EMS console redirection on the operating system that the boot entry loads.
The boot parameters described in this section enable EMS console redirection after Windows is installed. For information about enabling EMS during a new installation or upgrade of Windows, search for "Enabling Emergency Management Services" on the Microsoft TechNet website.
For a detailed example, see Boot Parameters to Enable EMS Redirection.