Final answer:
Microsoft has blocked macros in Office documents from untrusted sources to enhance security and protect users from potential threats such as malicious code.
Step-by-step explanation:
Reasons for Microsoft Blocking Macros from Running
Microsoft has blocked macros from running in files from the internet to enhance security. Macros are sequences of instructions that can automate tasks in Microsoft Office documents and are often used for repetitive operations. However, macros can also include malicious code that can harm a user's computer or compromise sensitive data. By default, if a file is downloaded from the internet or another untrusted source, Microsoft Office programs will block macros to prevent potential security threats.
To protect against these threats, Microsoft Office employs security features such as disabled macros with notification. Users can enable macros for a particular document if they trust its source, but this action requires a conscious decision and an understanding of the potential risks associated with enabling macros.