how difficult to clean install Windows 7 with Upgrade?

You want to upgrade the operating system of your Dell laptop from Windows Vista to Windows 7 operating system, so I want to tell you that Windows 7 operating system is the advance version of Windows vista operating system you can easily upgrade the operating system to windows 7 operating system, for this purpose you just need a internet connection, connect your laptop with the internet and then click on the control panel button and then upgrade option, when you click on the upgrade option then Windows will ask you about the latest version then , from there you can easily choose the new operating system and buy the operating system online with different payment option , with the help of this process you can easily upgrade your old operating system to new Windows operating system, I think this information helps you in upgrade.