Click on the Windows button.
Right click once on Computer and then left click on Properties.

Click on Device Manager.

Click on the arrow left of Modems.
Double click on listed modem.
In this case, mine is USB Data Fax Voice Modem.

Click on the Advance tab.
Click on the Change Default Preferences... button.

Go to Compression, drop the list down and select Disabled.
Click the OK button.
Click OK and close out of all the other windows.