Are you looking for a tutorial on how to Upgrade Windows Vista to Windows 7? Check out this excellent HD video demonstration and get to know everything about the Vista Upgrade process.
If you are upgrading from Windows Vista Home to Windows 7 Home edition or Vista Business edition to Windows 7 Professional or Windows Vista ultimate to Windows 7 Ultimate edition, you may go for this upgrade option. During the upgrade you will be prompted to download the latest files.It is recommended to download them. You will thus have to be connected to the internet during the upgrade process.
However, if you intend upgrading from, say, Windows Vista Home to a higher edition of windows 7 like the Ultimate edition, you will have to do a clean install i.e. you will have to back up all files and settings to an external device and install Windows 7 using a Windows 7 USB installer or a windows 7 DVD. This will wipe out everything on the hard disk before installing Windows 7.
If you are on Windows XP, check out this detailed tutorial on how to Upgrade Windows XP to Windows 7.