Some CORSAIR Pre-Built Gaming Systems, when set to sleep for an extended period of time, will set the computer into a "hibernate" state. This will not allow USB devices to wake the system up from sleep. The only way to wake the system this way would be by pressing the power button.
To enable the system to wake from sleep using a keyboard or mouse, follow these steps:
1. Disable Fast Startup: Control Panel -> Hardware and Sound -> Power Options -> System Settings
2. Enter the BIOS. To do this, click on the "Start" menu and then click on the "Power" button. While holding down the Shift key, click on "Restart". Once the computer restarts, select "Troubleshoot", then "Advanced options", and finally "UEFI Firmware Settings". This should take you directly to the BIOS.
3. Navigate to Settings -> Advanced -> Wake up Event Startup. Depending on the motherboard that is installed, this setting may be found in a different location.
For MSI motherboards it may look like this:
4. Enable "Resume from USB device" which will then allow the system to wake from sleep using a keyboard or mouse.