You can do a direct upgrade to Windows 7 from Vista, if you choose a correct edition for that (see Windows 7 upgrade paths for more info).
In this tutorial we will show you how to perform this upgrade
For the sake of this tutorial all files are stored on the Desktop. We will be performing upgrade from Windows Vista Home Premium 64-bit to Windows 7 Home Premium 64-bit.
Please download at least your network drivers before you attempt this upgrade. You might not be able to connect to the internet after the upgrade and need to install network drivers manually.
To perform the upgrade you will need:
If you will be unable to stop the update services try continuing with the upgrade however it can get stuck on the looking for updates online or at the initial steps of the upgrade.
Close command prompt
Wait for the extraction to complete
The folder will be in the same location as the ISO file, in case of our tutorial it is located on the Desktop.
Before continuing please shut down any running programs and turn off or remove any anti-virus and firewall software as they may interfere with the upgrade process and result in a fail.
After clicking on "Upgrade" the installer will check compatibility, it might ask you to make changes to your software (most commonly to uninstall one or few programs).
Remove anything that installer wants you to and reboot the computer.
After rebooting the computer make sure to stop the update services again (step 2 and 3).
Once the services are stopped you may continue from step 7.
The computer will reboot at one point and start transferring all of your data
And that’s it, you have successfully upgraded to Windows 7.