Hi predxeno,
Adobe Reader doesn't allow you to create PDF files--it's a PDF viewer. If you're looking to create a PDF file from a scanner, you can either use the software included with the scanner, or, better yet, you can use Acrobat. If you don't have Acrobat, you can try it free for 30 days. See www.adobe.com/products/acrobat.html for more information.
Best,
Sara