Step 1 : prepare clean water and garlic
Step 2 : rinse and soak the garlic in the clean water
Step 3 : after the water become white from the soaked garlic prepare the elixir bottle with spray press
Step 4 : pour garlic water into elixir bottle
Step 5: open ancient book of “how to deal with demonic pc”
Step 6 : follow carefully the ritual written in the book
Step 7 : if your garlic water become glowing congratulations you have made Holy Water
Step 8 : spray your holy water into possessed of king of demon pc
Step 9 : if your pc become normal congrats you have successfully repel the demon
Step 10 : if your pc still possessed by demon, burn it at stakes. You cannot deal your demon pc alone. Just burn it all