When installing something online, is it a lie to check off the "I have read and accepted the terms of agreement" boxes when you haven't really read through them because they are usually pages long?
By clicking the box, regardless if you read it or not, you automatically agree to the terms of service, or copyright laws, etc. In court it would not matter if you read all the pages or not. You simply agreed and clicked the box. It is the same idea as entering into a contract. That is why we don't enter into agreements haphazardly because we shouldn't be hasty in entering into contracts.
Even if we push that button, and it is to my own hurt, I must keep to the agreement, "He swears to his own hurt and does not change" (Proverbs 15:4). By clicking, "yes" you are simply agreeing to the company demands and laws about the product's use and are agreeing to be held responsible if you break them. If you violate the laws, then it is a sin. For example: Microsoft 360 has different licenses for the same product, one that allows a person to share with five other computers, while another only allows installation on one computer. It also has rules, such as I cannot modify Microsoft 360 programs. These are all generalities of majority of product laws or rules, but I tend to know the summary of the terms of agreement because they are all similar. If I am unsure on the products usage rights and agreements, before I do anything, I look it up to see if I can go further or not.
To be on the safe side, do as Jesus said, "But let your statement be, 'Yes, yes' or 'No, no'; anything beyond these is of evil" (Matthew 5:37). As a Christian, our word should be solid when it is given. I would suggest skimming the agreement to make sure you know what you're getting into and what you are supporting.