From this page you will be able to download firmwares, programs and there will also be links to some suggested apps. Some download links can be found throughout TechHub however all available downloads will be placed below. Some downloads may require a torrent client to download, if you do not have one you can download uTorrent from this link
Disclaimer: Piracy is against the law, any operating system downloads are for back up and restoration purposes only and you must have a legitimate product key to activate any software you download.
This is Windows 8.1 back-up media software that will create an iso on your system for you to use to restore your system at a later date, your product key is not required to create the media however when installing it, you will be prompted for the product key.
OS X Yosemite
This is a OS X Yosemite download via the Mac App Store and is free to download on your Mac
This is an iso download for Ubuntu and can be used to dual boot with Windows or as your main OS