I have a dozen friends using Linux Mint KDE 64 Bit. They are very happy with it. The updates are easy and the system is solid. And it is FREE! All were ex-Windows users and it was easy for them to convert over to Linux.
It was easy for them because I installed the OS for them. It is an easy install and much easier than any Windows install I have done. Only a personal password is required and NO authentication is required.
The beauty of Linux Mint is that I can instal the complete OS with all the important applications on one hard drive and then duplicate that hard drive for other computers. All of the necessary drivers and built in. Linux Mint finds the wireless hardware almost automatically and is a snap to setup. (Try that with Windows and the included wireless setup CD)
Also going from Linux Mint KDE 17 to 17.3 is as easy as one click of the Update Manager. The Update Manager automatically checks for updates and does NOT bug you with Pop Ups. The manager icon merely puts a blue dot in its icon's center when an update is avaliable.
I am sure happy I cut the ties with Microsoft a year and a half ago.
Here is a link if you are interested in trying it. The Download is free and no fees for using it. Linux Mint 17.3 "Rosa" KDE version.
Once you download the .iso file, burn it to a DVD and boot from the DVD to install it. It gives instructions as you install it.
PS I have installed Linux Mint on about 10 different laptops including 4 Dell 620 Latitudes and it works great.
Good Hunting... from Varmint Al