To get your CTH-670 working, you must avoid the "latest" drivers found on Wacom's main landing page. Instead, use one of the following:
Do not download drivers from random third-party "driver updater" software—they are usually malware. Below are the official Wacom-signed drivers that still function perfectly on Windows 10 (32-bit and 64-bit). bamboo cth-670 driver windows 10
Are you experiencing a or is the tablet simply not responding to pen pressure ? To get your CTH-670 working, you must avoid