How do they look for a power rating of a computer

To find the power rating:

• Check the PSU label: The most common way is to physically inspect the Power Supply Unit inside the computer case. There is usually a sticker or label on the PSU itself that clearly states its maximum wattage (e.g., 500W, 750W).
• Consult computer specifications: If the computer is pre-built, the manufacturer's specifications or documentation will list the PSU's power rating.