The Brktrt.sys file may cause this issue to occur.
To resolve this issue, update the Optus FACSys version 4.1 program to version 4.51 or to a later version after you verify compatibility with your operating system. For information about how to do so, please view the following Brooktrout Technology Web site:
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
To work around this issue, uninstall the Brooktrout Technology faxing software, and then remove the Brooktrout Technology fax/modem driver from your computer.
The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.