Welcome, b.
Twunk_16.exe is a component of TWAIN, the interface between applications and your scanner. PVD includes controls for adding scanned images, so I suppose the program is asking Windows for a TWAIN device on startup. I'm not sure why you would have or need Twunk_16.exe on your system, unless it's to support an old 16-bit program running in compatibility mode. I would try disabling it (by renaming), and see if that resolves the matter without other consequences.
In case it's relevant... I don't use the scanner feature, although I do have a TWAIN scanner on my Window 7 64-bit system. When I try an Acquire from scanner control, I get a "No TWAIN device found" error message.