First, did you leave it to dry for a few days before you tried using it? If you did not, it may well still have moisture inside. So you should consider leaving it be to dry for a few days (if you didn't before).
As for the setup utility.... try the following and see if it resolves the problem.
1. In the Aptio Setup Utility, select the "boot" menu and then select "Launch CSM" and change it to "enable".
2. Next select the "Security" menu and then select "secure Boot Control" and change to "disable".
3. Now select "Save & Exit" and press "yes".
4. Once you have done this, hold down the "power" button until the laptop turns off completely.
5. Now you want to power it back on and continually press the "F9" button for about ten seconds or until you are taken to the "Windows Recovery Menu".
6. In here select "Advanced Start Up" and then, once the recovery menu appears, select "Advance Options".
7. Choose "System Restore" and select a date prior to when the problem started.
The computer should now go through the restore process and then start normally for you.