This article will help you restore a device with all of your iCloud content, including photos. All this assumes you have a iCloud backup to work with.
A Mac computer is not needed. A Windows machine running iTunes works as well. Good luck!
If you are trying to access your photos on your PC, rather than restore them to an iOS device, there are a few ways to do this. One option is to create a shared photo stream that contains the photos you want as a public website and invite yourself (see http://help.apple.com/icloud/#mmc0cd7e99), then go to the public website on your computer and download the photos (see http://help.apple.com/icloud/#mm5669f3a5).
A second option is to save the photos to your camera roll on your iOS device (if not already there), then import them to your computer as explained here: http://support.apple.com/kb/HT4083.
A third option is to use an app like PhotoSync to send them to your computer using wifi.
A forth option is to sign into your iCloud account on your PC and enable photo stream (see http://www.apple.com/icloud/setup/pc.html). This will allow you to access photo stream photos.