Check if any devices is waking up your PC then disable the option that allows them to wake up your PC.
Open Command Prompt and type 'powercfg -devicequery wake_armed' and hit Enter
You will see a list of devices that could wake up your PC.
Go to Device manage locate the device on the list, right-click and select Properties.
Click the Power Management tab and uncheck the box 'Allow this device to wake my computer'.
Click OK .
Repeat these steps for other devices that could wake up your PC.