If you have older machines running Windows XP, then Microsoft will cut-off support of the operating system on April 8, 2014. That means no more patches, no more new software versions, no more drivers for new peripherals–and most importantly, no security updates and patches.
If you have an older machine that is running properly with XP, then you will probably find that installing Windows 7 or 8 will make it run like molasses in January. Most machines running XP don’t have enough memory to run Windows 7 or 8 efficiently.
I’ve been using Ubuntu 12.04 because it is the most secure of all the current OS offerings. The CESG, the UK government’s arm that assesses operating systems and software security agrees with me. Ubuntu also has the largest collection of applications in the Linux world.
Zorin OS 7, is also a good option when switching from Windows XP. It is faster, looks better and offers better performance than Windows, yet its user interface is similar to Windows and intuitive for long-time Windows users. It allows you to run Windows programs using WINE and PlayOnLinux emulators, as will other Linux distributions.
The US Department of Justice has “found” that Microsoft Windows is run by more than 95% of personal computers and that means that there are thousands of programs that will only run on Windows. WINE and PlayOnLinux allow you to use familiar programs to avoid a steep learning curve.