NOTE: this can be done without editing the registry, at least as of July 2014, by going to the PC Settings app from the Start Screen (the toggles are found under PC and Devices > Corners and Edges). Charms remain accessible by hovering in the bottom right corner.
You can, by making the appropriate changes in the registry, as follows:
Disable Charms Bar corner activation
To disable the activation of the Charms bar when you move your mouse to the top or bottom right corner of the monitor, you need to get your hands dirty in the Registry.
Press Windows-r and type regedit in the run box and then enter to load the Windows Registry editor. Accept the prompt that appears. Use the left sidebar menu to navigate to the following key in the Registry:
Right-click on ImmersiveShell and select New > Key. Name that key EdgeUI. Right-click on EdgeUI and select New Dword (32-bit) Value and name it DisableCharmsHint. After you have created the value, double-click it and change its value from the default value of 0 to 1.
This disables the corner mouse over interface on the right side. If you ever want to enable the feature again, simply change the key back from 1 to 0 to do so.
Disable Apps Bar corner activation
If you have skipped the above paragraph go back and follow the instructions to create the EdgeUI key in the Registry. Right-click EdgeUI afterwards and select New Dword (32-bit) Value from the context menu and name it DisableTLcorner. Double-click the new entry and change the value to 1 from its default value of 0.
If you ever want to restore the corner activation, simply switch the value back to 0 to do so.
Source: Disable Windows 8 mouse over corner interfaces