Windows Update automatically patches security holes and brings software and stability updates (if set to do so) and therefore enhances your computer's security. It is strongly recommended to keep the feature turned on to stay safe online.
In Windows XP, it is accessible via Start menu, or Tools / Safety menu of Internet Explorer. You must have Service Pack 3 installed to use automatic updates in Windows XP.
In Windows Vista and 7, Windows Update is located in Control Panel.
Windows 8 has a simplified Modern UI/Metro-style app and the traditional Control Panel version that allows full configuration.
In Windows 8.1, modern app offers access to all settings (and the traditional Control Panel app is still there, too).
Non-Microsoft programs can be kept up-to-date with free Secunia PSI.
You should ensure you have enough free disk space before installing updates - Windows runs at its best while at least 10% of system partition capacity is free; but at least 1 gigabyte of available space is recommended. For Windows Service Packs, several gigabytes of free space might be required.
In Windows 8 and 8.1, automatic updates are downloaded only on non-metered connections to avoid high charges on mobile (GSM, 3G, 4G, LTE) and dial-up connections. You can still force Windows Update to download and install the patches on metered connections.
If Windows Update constantly displays errors before or after checking for or installing updates, tries to apply the same updates repeatedly or completely fails to check for updates, read the Repair Windows Update article for easy and automated troubleshooting and repair options.
Windows XP without Service Pack 3 always fails to check for updates. Please apply SP3 to continue or start using Windows Update.
If Automatic Updates/Windows Update has been turned off for a long time and you would like to apply updates now, make sure you perform a full anti-virus scan with free products like avast! Free Antivirus, Microsoft Security Essentials or Windows Defender (only in Windows 8 and 8.1) first.
Then scan for other malware with Malwarebytes Anti-Malware to be sure that your PC is not infected.
Having a complete backup of your computer is also a good idea in case something goes really wrong.
Accessing Windows Update configuration
In Windows XP, you can launch Windows Update by opening Start menu (keyboard shortcut Ctrl+Esc) and clicking Control Panel.
If Control Panel is in Classic Mode, double-click Automatic Updates.
If Control Panel is in Category View, open Security Center and then click Automatic Updates.
In Windows Vista and 7, click Start button or press Windows Key on your keyboard and type the word update into Start menu Search box. Then click Windows Update.
In Windows 8, open Settings search using keyboard shortcut Windows Key+W, type "update" into Search box and click Install optional updates. Please note that clicking Windows Update will take you to Windows Update tab of PC Settings app that provides no configuration options.
In Windows 8.1, click the colorful version (not the cogwheel icon) of Windows Update to use the traditional Control Panel version. The Modern UI app equivalent is described later in this article.
If there are updates available, Windows Update icon will be displayed in Taskbar Notification Area. Click it to open Windows Update in Windows Vista, 7, 8 or 8.1. In Windows XP, this will not open configuration options, though.
Automatic Updates/Windows Update is now open. First let's select a good time for updating Windows and other Microsoft products.
While Microsoft publishes security and stability updates on second Tuesday of every month, there are times when critical fixes, stability updates and Service Packs are released outside the schedule. That's why you should set your computer to look for available updates on daily basis.
In Windows XP, make sure you have the Automatic (recommended) option selected. Then select Every day and set the time when your PC is most probably turned on in the Automatically download recommended updates for my computer and install them combo boxes.
Click OK to close the window and apply changes.
In Windows Vista, 7, 8 and 8.1, click the Change settings link on the left:
In the Choose how Windows can install updates window, make sure Install updates automatically (recommended) is selected.
Next, ensure that both Give me recommended updates the same way I receive important updates and Allow all users to install updates on this computer boxes are checked.
In Windows Vista and 7, select Every day and set the time when your computer is most probably turned on in the Install new updates combo boxes. Do not close the Windows Update window yet!
In Windows 8 and 8.1, click the Updates will be automatically installed during the maintenance window link instead. Then, in the Automatic Maintenace window, set the time when your PC is most probably turned on in the Run maintenance tasks daily at combo box. Click OK.
Finally, click OK to apply settings. Do not close the Windows Update window yet!
In case you have already enabled Microsoft Update in Windows Vista and 7, there are two more combo boxes available - Give me updates for Microsoft products and check for new optional Microsoft software when I update Windows and Show me detailed notifications when new Microsoft software is available. Make sure both of the options are turned on. You can skip the rest of the article then.
Please note that if your PC is not turned on (or not connected to the Internet) at the scheduled update time, Windows will still check for updates the next time you start or restart your computer.
Microsoft has improved the Modern UI/Metro PC Settings app in Windows 8.1 a lot. It also brings Windows Update configuration up to the same level with the traditional Control Panel version.
To access the Windows Update app, open Search everywhere (Windows Key+Q) or Settings search (Windows Key+W), type "update" and click either Windows Update settings or the Windows Update item with cogwheel icon.
PC Settings app opens in Update & recovery, Windows Update tabs. Click Choose how updates get installed.
Make sure that Important updates combo box is set to Install updates automatically (recommended). Below there is a reminder that updates will be downloaded and installed on non-metered (e.g. not 3G, LTE, pay-per-megabyte connections, etc) connections only. To see instructions on how to change this, scroll upwards.
Then tick the Give me recommended updates the same way I receive important updates check box. This will apply stability updates with automatic security updates.
Next, put a check mark in the Give me updates for other Microsoft products when I update Windows check box. This means that other Microsoft software, such as Office products and Windows Live Essentials will also be updated automatically.
Finally, click or tap Apply.
Windows 8.1 users can safely skip the rest of this tutorial if they enabled Microsoft Update in the Modern UI app.
Microsoft Update is like an add-on to Windows Update/Automatic Updates - it enables updating other Microsoft software such as Microsoft Office products (Word, Excel, PowerPoint, Access, etc), and installing free software such as Microsoft Security Essentials or Windows Live Essentials.Click here to show or hide instructions for turning on Microsoft Update in Windows XP
Open Start menu and click Windows Update on top of All Programs menu. You can also open Safety menu in Internet Explorer 8 (Tools menu in Internet Explorer 6 and 7) and click Windows Update.
Windows Update will check its version and Automatic Updates settings on your PC first. This might take several minutes if you run it the first time.
Please note that Service Pack 3 for Windows XP must be installed to continue.
After the checks are complete, click Go in the Get Microsoft Update today! section.
Click Start Now on the Microsoft Update introductory page.
Ah, the license agreements! To put it short: as with any other product, you are responsible for everything and there is no way that the product creator is responsible for something.
Next, Microsoft Update software will be downloaded (this might take a few minutes on slower connections) and a yellow Notification Bar appears. Click the bar and select Install ActiveX Control in the menu to allow installation of Microsoft Update.
Next, Internet Explorer pops up its own Security Warning. As long as Publisher is Microsoft, it is safe to click Install here.
After a short while, the setup is complete and you can click Check for Updates.
Microsoft Update is now available in Start menu, All Programs. Also, the Windows Update command in Internet Explorer now automatically leads to Microsoft Update.
If you have not yet enabled Microsoft Update, there is a link titled "Get updates for other Microsoft products". Click the Find out more link:
If Windows Vista, 7, 8 or 8.1 has already received and installed an update to Automatic Updates mechanisms, you will just see the following dialog.
Click the Yes, tell me about new software (recommended) button:
Then click Continue or Yes in User Account Control prompt and Microsoft Update is ready to rock.
User Account Control will ask whether you want to allow Microsoft Update. Click Continue or Yes.
Windows Update will then check for updates. Don't hold your breath, for this might take several minutes.
Again, if you encounter repeated problems with Windows Update, read the Repair Windows Update tutorial.
Windows 8 and 8.1 allow setting a network connection as a metered one. This means that no security and driver updates are downloaded over such networks. Good examples of metered networks are pay-per-megabyte connections, 3G and LTE modems: in short, all networks with data transfer limits.
If your PC has only a metered connection, you should enable update downloads to stay secure.
Use keyboard shortcut Windows Key+I to open Settings charm and then click or tap Change PC settings in the bottom of the bar.
In Windows 8, open Devices tab from the left and then set Download over metered connections slider to On.
You can close the PC Settings app using keyboard shortcut Alt+F4 or by dragging the app down from the top with mouse pointer or your finger (only on touch screens).