Article updated for Windows 10 and other versions.
Windows update System Tray icon reports "Windows can't check for updates"
Windows Update hangs for hours at 0%, 44%, 90% and other percentages
Windows update "Checking for updates" status bar / progress bar does not move
The Windows Update Status indicator runs, but shows no activity or
The Windows Update Control Panel Page shows a Red-shield icon and warns you should run an update regularly, but it does not actually run the update.
Windows Update may be corrupted. Microsoft has a utility that can test and fix this problem. Corruption can especially happen if an older computer is brought online after a long period without updates.
You can run these steps even if you are not sure the symptoms match your problem. There is no harm, other than taking the time.
These steps resolved the problem on my computer, but expect
to take an hour or more to run -- plus the time it takes to catch-up
on the Windows updates.
A. Confirm the PC's Date and Time are correct. (Click the time in the lower-right System Tray). Windows update panics if this is too-far out-of-norm.
B. If you have not already done so, reboot the PC.
Reason: Sometimes Windows update needs to update itself before it can update other things and this often requires a reboot.
C. Check the Windows Update status again, giving it 20 or 30 minutes to see if the status changes. Some updates, such as the Windows 10 Anniversary update, are slow at updating the status.
Windows 10 Update can be found in "Settings", under Updates and Security. Or use Cortana, searching for "Windows Update", finding "Check for Updates". For Windows 7, see the Control Panel, Windows Update
D. If still hung, continue with these steps, which depend on which version of Windows is running.
Decision: What specific version of Windows are you running.
Launch Windows Explorer (File Explorer, not IE).
In the tree-side, locate "This PC", "My Computer" (or "Computer").
Other-mouse-click "This PC" and choose "Properties" from the context menu.
Note which Operating System is installed, which Service Pack, and whether it is 32 or 64-bit.
Windows 10 Home / 64-bit Operating System, x64-based processor
Windows 8 64-bit SP1
Windows 7 64-bit
Windows Server 2012
1. Run the CMD Prompt as "Administrator"
From the Windows tile-menu (or from Cortana search, search for "CMD"), locate the Command Prompt icon, but do not click to open.
(In Windows 8, open the main Start tile screen and begin typing "CMD")
2. Other-mouse-click the Command Prompt icon, choose "Run as Administrator".
DOS runs as an "elevated command."
3. Type these two commands, pressing Enter after each. You must be running in Administrator mode.
DISM.exe /Online /Cleanup-image /Scanhealth
DISM.exe /Online /Cleanup-image /Restorehealth
The routines may have hesitations while running. Wait for "operation completed successfully".
The hard drive light will show activity even if the status bar does not move.
4. When done, close the DOS Command Prompt window "X".
5. Reboot (recommended)
6. Open the Windows "Settings" menu, run Update & Security manually; click "Check for Updates".
1. Using Internet Explorer (it must be IE), go to this site:
2. Scroll to the Windows (7) section.
3. Download and run the correct version (noting which version of Windows, 32 or 64-bit, etc.).
Installng and running will take up to an hour and may have long hesitations on the status bar -- allow it to complete; note the hard drive light will be busy even if the status bar does not move. Microsoft notes this tool, the "Windows Update Standalone Installer" is updated regularly and you should always use the most current version, as downloaded.
4. Open the Control Panel and run Windows Update again. The problem should be resolved. As always, wait a respectable amount of time to give slower-updates time to update the status indicator.
If you are still having problems:
This low-risk solution has been reported to help, although I have not needed this in my experience.
a. Start an elevated Command Prompt: (From the Start-menu, 'other-mouse-click' the Command Prompt icon, choose "Run as Administrator")
b. Type this command and press Enter.
netsh winhttp reset proxy
c. Attempt Windows Update again.
d. Consider stopping Netflix and other streaming services while running large updates and patches.
Windows 8.1 Upgrade not in Windows Store
Delete Windows.old after upgrading to Windows 8.1