My host is ubuntu 11.04. The guest is WinXP VirtualBox is 4.0.10
The serial port works well with putty in ubuntu.
I setup as: COM1/4/0x3F8/Host Device/ Port Path: /dev/ttyS0
Then I close putty, to make serial port is free. After windows XP and Device Manager started, I see there is a LPT1 instead of COM1 under "Ports(COM & LPT)"
I followed the procedure in this topic( How to access serial ubuntu host serial port on VirtualBox guest OS ), but the issue keeps not resolved.
Thanks for any help.