There is only one file type that uses the .WTC extension:
Logitech Webcam File
File named watch.wtc and used by Logitech Webcam Software, an application used for interacting with Logitech webcams; created as an empty file and sometimes saved to the desktop and other times to the My Pictures directory; can be deleted.
|Logitech Webcam Software||Free|
Updated: July 30, 2011