Here are a handful of useful links:

Microsoft Security Essentials - Download the latest version of the popular and free Anti-Virus program from Microsoft

Microsoft Windows XP Service Pack 3 - Download this essential Service Pack for the Windows XP Operating System

Microsoft Windows Vista Service Pack 2 - Download this essential Service Pack for the Windows Vista Operating System

Microsoft Windows 7 Service Pack 1 - Download this essential Service Pack for the Windows 7 Operating System

Microsoft Windows 8.1 Update (64bit) - Download this essential Update for the WIndows 8 Operating System

Classic Shell - Download this essential tool for Windows 8 and 8.1 which adds the start button and start menu

Microsoft Internet Explorer 11 - Download the latest Internet Explorer for your computer (Windows Vista, 7 and 8 only)

Microsoft Internet Explorer 8 - Download the latest version of Internet Explorer if you are running Windows XP

Microsoft Office Compatibility Pack - For Word, Excel, and PowerPoint 2000, XP and 2003

Microsoft Windows Live Essentials - Download Windows Live Mail which is a great little email handling application

Microsoft Windows XP Mode for Windows 7 Professional/Enterprise/Ultimate - Run old programs in XP mode on Windows 7

Microsoft OneNote 2013 - Capture thoughts, ideas, and to-dos and sync them to all your devices

Skype - Download this great application that enables you to video and or voice chat with someone over the Internet

Adobe Acrobat Reader - Download the latest version of the popular PDF reader

Adobe Flash Player - Download the latest version of Adobe Flash Player

Adobe Shockwave Player - Download the latest version of Adobe Shockwave Player

Autodesk DWG TrueView - Download the latest version of the Autodesk CAD drawing viewer

Slysoft Virtual Clone Drive - Download the latest version of this ISO reading application

Josh Madisons Convert - Download this great little unit conversion tool

Trend HiJackThis - Download this great little virus removal tool

Rarlab WinRAR - Download this great little compression tool that unpacks and packs WinRAR files as well as WinZip files