MAKE a full image backup of your old system before installing Windows 8.
That's the best advice I can give to anyone wanting to overwrite their old Windows system with the new OS while keeping their personal files, settings and applications.
I generally like Windows 8 and have no problem with Microsoft ditching the old Start menu, but its ditching of the F8 diagnostic option at startup in favour of compulsory automatic repairs can be really frustrating.
Like lots of early adopters, I installed beta versions of Window 8 on a virtual PC using Oracle's VirtualBox where it ran without major issues - a virtual PC offers an artificial pristine environment after all.
And if you buy a new device with Windows 8, you too may not have any hassles. These issues are more likely to hit those upgrading older Windows systems.