There are a variety of other free PDF reader programs if you don't want to install Adobe Reader.
Windows 8 comes with a PDF reader installed if you don't want to use Adobe Reader.
Decline the McAfee offer. When installing Adobe Reader, a box will be automatically checked to add McAfee to your computer. Most users likely will not want this, so make sure to uncheck the box.
Double-click a PDF file after installing Adobe Reader. For most users, Reader should open automatically, displaying your PDF file.
Enter the password if required. PDF files can be password-protected by the creator, so you'll need the correct password if one is required.