My Firewire/Thunderbolt device is not working in Windows virtual machine.
Firewire/Thunderbolt device misconfiguration.
If you have the Firewire/Thunderbolt storage device, please configure it as described in KB 5161.
Devices like scanners and printers can be used in Parallels Desktop via Sharing printing feature.
To find out how to use the external graphics card in Parallels Desktop, see KB 124266.
Having the external sound card gives you an opportunity to share sound between Mac and Windows sides. Make sure to enable the following feature in the virtual machine's configuration > Hardware > Sound > Sync volume with Mac.
Some external displays that connected to the Mac via Thunderbolt can be used in Windows virtual machine as well.
To avoid issues with the display connected this way, make sure it is not forwarded directly to the virtual machine. You can find out by going to Mac menu bar > Devices > USB & Bluetooth. Your external display must not be checked in the list.