I don't have CVI6 but according to the Help in CVI7.1/W2k you must use the Registry.
Use the help search function to find 'useDefaultTimer'.
CVI 7.1 Help says
Timer Options�useDefaultTimer
You can configure LabWindows/CVI timer options in the Registry. The timer option, useDefaultTimer, is a DWORD value; 0 indicates False and 1 indicates True.
If you set the useDefaultTimer option to True, LabWindows/CVI uses the default Windows timer to implement the LabWindows/CVI timing-related functions, such as Timer and Delay. The default Windows timer provides a resolution of 10 ms.
If you set useDefaultTimer to False, LabWindows/CVI attempts to use the performance counter timer. The performance counter timer provides a resolution of 1 ms. If the performance counte
r timer is not available, LabWindows/CVI uses the multimedia library timer, which provides a resolution of 1 ms.
The default value for useDefaultTimer is False.
