On the whole, it is not a good idea to use the office laptop for personal use. For one thing, you will, unknowingly, by bringing in personal data to your office computer. If such data is lost or stolen, you will be in a lot of trouble.
Also, it is a good idea to stick to the rules of your office. If your office does not allow you to use the computer for personal use, it is for a reason. Therefore, it would be better if you followed the rules.