Parallels Workstation 2.2, 25-49u, EN, MNT WWL2XM-03-EN 用户手册

Parallels Workstation allows up to four serial ports to be connected to a virtual machine. 

Serial Port Options in Windows primary OS: 

 

Device status: 

ƒ  If you wish to temporarily disable operations with a serial port without deleting it from 

configuration, deselect the Enabled check box.  

Note: If you start the operating system with the serial port disabled, it can not be 
connected/disconnected while the VM is running.