It's a pity that a PDF reader isn't included when Windows 7 is released.  However, you can download and install a light-weight yet powerful PDF Viewer to serve as part of the operating system to view, print, and convert PDF. This PDF viewer is free.
Downloads: 41042 - Freeware - Download Now

Offer nice capabilities, performance, and versatile functionalities to open, view, rotate, print PDF files and convert PDF to TXT, JPG, GIF, PNG, BMP, EPS, EMF, TIFF. It's useful for those that typically stick to the Windows 10 experience.
Downloads: 29443 - Freeware - Download Now

Open, view, review, print Adobe PDF files, and convert PDF to TXT, BMP, JPG, GIF, PNG, WMF, EMF, EPS. This lightweight yet full-featured free PDF viewer supports zoom in and zoom out, page rotation, and PDF slide show. Designed for Windows 7.
Downloads: 38074 - Freeware - Download Now

Software for the management and viewing of all common image, multimedia (AVI, MPEG, MP3, etc), Office, text and web files, allowing you to rapidly search and categorize files using keywords and descriptions (which can be automatically generated).
Downloads: 27095 - Shareware - Download Now

Easily copy pictures/videos from dig cameras to your computer, organize, and share them. Create your own screensavers, slideshows, email, and publish photos to your own web page or blog. Backup and restore features protect and preserve your photos.
Downloads: 20888 - Shareware - Download Now