How to Fix Server Error Code 503 Service Unavailable Issue


by Eddie Bradbury · January 20, 2016


Users may receive some error messages while using browser to surf on the Internet, and Error Code 503 is one of the common errors met with when the web server is currently unable to handle the HTTP request due to a temporary overloading or maintenance of the server. Have no idea how to troubleshoot this problem? This tutorial will give some tips on troubleshooting Service Unavailable issue and show you detailed steps to fix Windows Error Code 503 both manually and automatically.

Get More Details about Error Code 503:

It should be pointed out that users may encounter the error message of code 503 under quite different circumstances. In most cases the 503 error is associated with the web site’s server or the server software, and it can appear in any browser in any operating system. Some users said they get this error message when trying to browse to local host. Sometimes this message indicates that the PHP processes are crashing while executing a script, and the most common cause of this problem is buggy PHP code, such as buggy WordPress plugins or slow scripts. This problem can also be caused by buggy third-party PHP extensions or your server running out of memory. Here are some common error messages related to 503 error code that you may receive:

  • 503 Service Unavailable
  • HTTP 503
  • HTTP Error 503
  • 503 Error
  • Error 503 Service Unavailable
  • Http/1.1 Service Unavailable
  • 503 Service Temporarily Unavailable

Then how to repair Error Code 503 effectively? You can review Windows NT event logs to identify the root cause, and here are some options to help you troubleshoot Error Code 503. Try the methods below and see which one helps solve your issue.

Feasible Approaches to Fix Error Code 503

Method 1: Run Command Prompt with Administrative Rights

Sometimes your browser cannot connect to http server, or the proxy connector hides the ephemeral ports, and then error message appears. If the Error Code 503 occurs when the http server is too busy or not maintains properly, you can implement the following method to get rid of HTTP Error 503(Service Unavailable).

On Windows 7/Vista:

  • Click on Start menu and type “cmd” in the search box.
  • Right-click on Command Prompt, and then click Run as administrator.
  • Type the password if you are prompted for an administrator password.
  • Type “regsvr32.exe xxx.dll” (replace xxx.dll with the dll in question).


On Windows 8/8.1:

  • Move mouse cursor to the lower-right corner of the screen.
  • Click on Search and then type “command prompt” in the search box.
  • Right-click on Command Prompt and then click Run as administrator.
  • Click on Allow if you are prompted for a confirmation.


  • Copy the bellow code and paste in the Command Prompt: netstat -na >C:netstat.txt
  • Hit Enter key and go to the Windows service panel to restart the Proxy agent service.


Method 2: Restart Router and then Your Computer

While Error Code 503 is most likely associated with the website you’re visiting, it’s possible that there is an issue with your computer’s or router’s DNS server configurations, especially when the message shows up like “Service Unavailable – DNS Failure”. In that case, a simple restart of your PC and DNS might fix the problem. If not, pick up new DNS servers might be another try.

Method 3: Make Sure All the Services are Running

The “503 Service Unavailable” error message may occur in your browser if the System Attendant service and the Information Store service are not running, or if the Exchange 2003 services are not running under the Local System account.

  • Click on Start menu > Control Panel > System and Security > Administrative Tools.

System and Security

  • Click on Services to open a new window, locate Microsoft Exchange Information Store and Microsoft Exchange System Attendant under the Name column.


  • Check if they are started. If not, right-click on the service name, and then click Start.
  • Look for Local System under the Log On As column. If they are not logged on under the Local System account, right-click on the service name, and then click Properties.


  • Click Log On tab and then click on Local System account under Log On As.

Method 4: Restore System Settings to an Earlier Date

System Restore is a Windows utility that allows a user to restore their computer data to a specific former state (known as a restore point). As a way to undo system changes (including the changes of system settings, Windows registry files and installed applications), it can be used to recover from system malfunctions or other problems. If the aforementioned ways fails to fix Error Code 503, try System Restore by following the next steps.

  • Start your computer and log on as an administrator.
  • (Right) click on Start button, type “system restore” in the search box.
  • Click System Restore in the list of results, and type the password or provide confirmation if you are prompted for an administrator confirmation.


  • Click Recommended restore and then click Next. Or you can click Choose a different restore point, select the specific point you want and then click Next.
  • Review the restore point, and then click Finish.
  • Restarts the computer when the restoration is finished.


Method 5: Fix Error Code 503 with Repair Tool

There can be many events which may give arise to the system files errors, and Error Code 503 can be caused in one way or another by misconfigured/damaged system files in your windows operating system. An incomplete uninstall of applications, adware/spyware attack, or even improper shutdown of computer may result in the deletion or corruption of the entries in the windows registry.

Actually, many system errors can be avoided if you keep Windows registry in the best condition. That is why you are supposed to clean and repair the registry at regular intervals. If you wanna do it effortlessly, we strongly suggest using an automated fix tool which can scan, diagnose and then troubleshoot your system errors with advanced technology. To fix Windows Error Code 503 automatically you need to follow the steps below:

Advanced Fix

  • Launch the fix tool and click on the Scan button to scan the Windows Registry.
  • Click on Fix button to resolve all the detected issues listed in the scan results.
  • Restart your computer to take effect after the fixing process is finished.

This post offers 5 solutions to fix Error Code 503. In other cases the Windows firewall or antivirus software will block the http 8080 port and result in HTTP Error 503. If so you can disable the firewall temporarily to see if it helps fix Server Unavailable error.

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