16 bit error

On startup, I get an error box titled
“16 bit Windows Subsystem” with the message

SYSTEM\CurrentContolSet\Control\VirtualDeviceDrivers. VDD. Virtual Device Driver format in the registry is invalid. Choose ‘Close’ to terminate the application.

I found this key in HKLM. The multiword “VDD” had value c:\progra~1\symantec\s32evnt1.dll, along with a hell of alot of binary data.

Can you think of a reason this message would occur when no likely changes have occured?

Is the quickest fix a reinstallation?

Thanks