From the 'Settings' section of the PCCare screen, select the task you wish to change. Click on the 'RESTORE TO DEFAULT' button by that task, watch for the values to change, then click 'Update Settings'.
Please note this is a two-part operation - you must first 'Restore to Default' and then 'Update Settings' or the change will not take place.
As when changing any setting, you will have to wait for the "Settings updated successfully" window to appear in order to ensure that the system has recognized the change.
Restoring a setting to the default must be done uniquely for each task; there is no "restore all" control.