In order to update your Windows 7 operating system, follow the steps below:
1. Click on the Windows start button and type the "Update" into the search.
2. This opens up the Windows update settings page.
You can also access this page by clicking on control panel > System and Security > Windows Update.
If the automatic update is turned off by default then you can enable or disable it on this page.
If you click on the Windows update link then it should take you to the settings page where it allows you to "Check for Update".
You can disable the Windows update after successfully updating the system. This is to avoid automatic download of the system updates.
Whenever updates are arrived you can check them and then install based on the priority. This installs the update when you try to shutdown. So it takes some time during the shutdown and also during the boot time the new settings and updates are applied.
Your question seems to be a bit ambiguous. You have not made it clear as to whether you want to update your system to latest version or need to update to Windows 10. If you want to update to the latest version of the system, follow these steps -
1. Click on Start, search for the term Update and click on Windows Update in the search results.
2. Click on Check for updates on left hand pane. Wait till Windows searches for the available updates.
3. Select the important updates to install.
4. Go through the list of available updates and mark the check boxes against the items you would wish to update. Make sure all the updates marked Important are checked.
5. Click on OK.
6. Now click on Install updates.
Done! Your updates will be installed. You can set the system to receive automatic updates regularly. Your computer will keep downloading the updates as they are released and will be installed when you shut your computer down.