The
last folder in the path will differ depending on which Canon Transport
you're using:

For a Canon CR-50/80 the registry path would be:
HKEY_CURRENT_USER\Software\Canon Electronics Inc.\CeiVScan\CeiVSEagle
Add the DWORD value with the name WriteLog, and change Data to 1.
If you change the registry, the CeiVS.log file is created in the tmp folder.

type '%temp%' in the my computer file explorer.