What am I seeing?
You can't use USB Keyboard in DOS mode after executing Symantec Ghost*. However, the USB keyboard works fine in other DOS-based applications on Intel® Server Board S3420GP.
How to fix it
Disable the Port 60 / 64 Emulation under USB Configuration in BIOS by selecting BIOS > Advanced > USB Configuration > Port 60/64 Emulation > Select Disabled.