Delete FXSAPIDebugLogFile.txt is related to the Windows Fax and Scan service.

FXSAPIDebugLogFile.txt is related to the Windows Fax and Scan service.

To disable this service:

Control Panel > Programs and Features > Turn Windows Features On or Off

Under Print and Document Services, look for Windows Fax and Scan

Uncheck it, click OK, and restart

You can now delete FXSAPIDebugLogFile.txt

You can later re-enable the Fax and Scan service if something doesn't work right.