Which of the following characters is NOT allowed in a filename when renaming in Windows?

Correct option is C

The correct answer is (c)? (question mark)

Explanation:

• In Windows operating systems, certain characters are not permitted in filenames or folder names.
• The question mark (?) is one such invalid character because it is reserved for system operations, especially for wildcard search patterns.

Information Booster:

• Other not allowed characters in Windows filenames include:
  \ / : *? " < > |
• Attempting to use these characters while renaming a file will result in an error message.
• Windows filenames can include symbols like hyphen (-), underscore (_) and hash (#) without any issue.

Additional Information:

• Option (a) Hyphen (-) – Allowed; often used to improve filename readability.
• Option (b) Underscore (_) – Allowed; commonly used in programming and naming conventions.
• Option (d) Hash (#) – Allowed in Windows filenames, though some older web-based systems may treat it differently.
• Always use alphanumeric characters and safe symbols for compatibility and system stability.