id summary reporter owner description type status component version resolution keywords cc guest host 4992 Attaching to host serial port on Windows 7: Permission problem Steve Weidman "I am attempting to pass the RS-232 serial ports of the host operating through to the guest operating systems. I have fully functional COM1 and COM2 ports available and working in the host system. Serial Ports are set up in the guest operating system as Port 1, COM1, Host Device (COM1) and Port 2, COM2, Host Device (COM2) When I attempt to ""map"" these devices to the guest operating system, I receive the following error: ""Failed to start the virtual machine (''Windows 7 RC, Windows 98SE and Windows 95C report the same error)''. Cannot open host device 'COM1'for read/write access. Check the permissions for the device. (VERR_ACCESS_DENIED). Unknown error creating VM(VERR_ACCESS_DENIED). Details: Result Code: E_FAIL (0x80004005) Component Console Interface: IConsole {0a51994b-cbc6-4686-94eb-d4e4023280e2}"" The only way for the guest systems to start is to ""disconnect"" the serial ports. Host System Details: Windows XP Pro, Version 2002, Service Pack 3 Intel Pentium 4, 3.00GHz 3.00GHz, 3.5GB of RAM COM1 I/O 03F8-03FF, IRQ 04 COM2 I/O 02F8-02FF, IRQ 03 VirtualBox 3.0.6 r52128 " defect closed uart VirtualBox 3.0.6 obsolete RS-232 Windows Windows