| What We Support The following components are associated and supported by the Uncertain Tax Positions application. For further information, call 1-877-829-5969, and choose Option 2, or email:  provisiontechsupport@thomsonreuters.com.   Operating Systems Browsers Excel   Changes to Microsoft Windows XP Support With Microsoft ending support for the Windows XP operating system in April 2014, ONESOURCE Tax Provision will begin a phased approach to end support of Windows XP, as well. Beginning in April 2014, we will no longer design or develop features specific to the Windows XP operating system, and will no longer perform in-house testing against the Windows XP operating system. We will communicate any additional information during our upcoming releases.   *Compatibility mode |