Normally an "upgrade" will not harm your local data nor your programs and drivers, however.....
It is a major move when performing an Operating System upgrade and consequently, all due care should be taken to keep your data and system safe before undertaking such an operation.
My recommendation would be to perform a full system image first to external media and then supplement / augment that, by performing another file and folder backup of anything you consider critical.
Usually a copy of your user profile folder will get most everything, but there are some programs like QuickBooks and such that store their working files in other locations.
Short answer.... No, it will not.
If you have Windows 7 running and you open the Windows 8 DVD in explorer and run Setup.exe from there it should perform a normal upgrade, but....
Again, it's a rather huge procedure and a lot of things have to work just right and a lot of us know that, that has not always been our experience.
So, upgrading your operating system, without first making absolutely certain that all your critical data is completely safe from harm, in my opinion is not a good nor safe way to proceed, as I thought I'd already made clear in my post above.
Generally, your data will not lost, when you install Windows 8, the setup wizard asks what you would like to do with your existing files. Upgrading from Windows 7 gives you the most options because you can choose to copy over user files, settings and applications. If you don't tell the wizard to carry over anything, it creates a folder named Windows.old, stores your personal files in it and deletes everything else before installing Windows 8.
Tips: After you install Windows 8, make your next upgrade easier by keeping important files that you create in a common location. For instance, if your old operating system had important documents scattered across different locations on your hard drive, Windows may not have copied them to the Windows.old folder during the upgrade. Keeping critical documents in your Documents folder ensures that they survive when you install a new operating system and choose the option that instructs windows to tell Windows to create a Windows.old folder.