@cheesam#163172
I've done it, these are the lines to run in terminal in order to change the values.
Run each line and edit "Windows 10" to the name of your VM.
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemVendor" "HP"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemProduct" "ENVY dv7"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemVersion" "<empty>"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemSerial" "string:%random%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemSKU" "string:%random%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemFamily" "<empty>"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemUuid" "d18cce0e-44f9-4a74-808c-ff8ff99889da"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBIOSVendor" "HP"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBIOSVersion" "string:%random%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBIOSReleaseDate" "%SYSdate%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardVendor" "HP"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardProduct" "ENVY dv7"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardVersion" "string:%random%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardSerial" "string:%random%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardAssetTag" "string:%random%"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardLocInChass" "<empty>"
VBoxManage setextradata "Windows 10" "VBoxInternal/Devices/pcbios/0/Config/DmiBoardBoardType" "10"