HTTP IIS7 Error 503: The Service Is Unavailable

After acquiring a new machine or making a configuration change, it is possible that your Internet Information Services (or IIS) goes completely missing and you receive the error, 503 service is unavailable”. Sometimes, you might also encounter the “server not available” error. It’s frustrating and can definitely be confusing to encounter! But don’t worry, I’m going to help you get your computer back on track in no time.

Often people notice themselves asking this question on the forums once somebody posts one thing like “Help, I’m affected by IIS 7 and currently my application doesn’t work!”. Huh, what doesn’t work? Once your website stops operating, the primary factor you would like to try is to verify that the error truly is there before going any further. IIS 7 has far better error messages which will typically tell you specifically what the matter is, and assist you with fixing it.

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Unfortunately, getting to the source of the error is the primary challenge. Don’t panic! Not panicking is the first and most important step to the troubleshooting process, read more about my thoughts on not panicking here. Let’s look at a couple of things you might have to try:

1) Disable IE “Friendly protocol error messages.”

IE can by default replace the particular error messages returning from the server with a “friendly” error message, that hides the error contents we’d like to check, as an example, for a 404 Not Found error, you will instead see the following:

IE Friendly Error

To disable this and see the actual error returning from the server, you would need to go to Control Panel, Tools, then Internet Options. Select the Advanced tab, and remove the “Show friendly protocol error messages” checkbox.  Then, shut the browser, open it once more, and re-request the page.

Disable IE friendly protocol error messages

Now, suppose you still see the generic “cannot show the web page” or “page not found” error. This can be caused by IE failing to reach your website; thus there’s no server error message to see.

If you don’t wish to mess with IE for troubleshooting (especially if you think you’re obtaining cached pages, as a result of IE’s super- aggressive caching). Use one of your favorite HTTP tools instead and make the request that way.

So, What Does This Even Mean And Why Is It Happening?

According to TechTarget, Internet Information Server “is a group of Internet servers (including a Web or Hypertext Transfer Protocol server and a File Transfer Protocol server) with additional capabilities for Microsoft’s Windows NT and Windows 2000 Server operating systems.”

There is a WAS service, the acronym for Windows Activation Service and is assigned with the task of managing incoming http requests. Error 503 is generated when WAS fails to handle these requests.

This 503 service is unavailable error can appear in different forms depending on your server and the page you are visiting. This error implies that the website’s server is simply not available at the moment. 503 can appear in Windows 10, 8 or even Mac or Linux and even your smartphone within the browser window. It can appear in different versions like 503 service temporarily unavailable, 503 Error, 503 Unavailable, HTTP 503 unavailable, HTTP error 503 and Error 503 service unavailable. You look at other errors to see if the one you have encountered is related to this tutorial to solve issues. All of these point out that your server is not present for carrying out http requests.

“Error is discipline through which we advance.” – William Ellery Channing


There are many reasons this error can appear. Most of the time, 503 errors appear when the server is too crowded with other requests or under maintenance. In simple words, the browser is unable to make a connection with the web server at the specified address. Sometimes, the error has nothing to do with IIS and it could mean that your browser was unable to resolve the server hostname that was requested. Also, the server could not be reached because of connectivity issues or any problem related to the firewall. If it will be related to IIS, then there is a high possibility that your site is facing configuration issues. You can read about the root causes of error 503 in detail on the Microsoft website.

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Other reasons include when the Application Pool identity of the corresponding web application has malfunctioned, stopped, or disabled. In some cases, the identity has incorrect settings and following the background can offer more insight as to how you can solve it.

Application Pool identity allows running of the application pools under a unique account so you do not have to create and manage local or domain accounts. This feature has been available since Windows Server 2008. If you want a tutorial related entirely to the application pool, please refer to here.

If you want to extensively understand what Hypertext Transfer Protocol (HTTP) means, you will have to understand that there are methods that point towards an action that is supposed to be performed on the server for a particular URL. To read more about what these methods imply, you can refer to my website article about Understanding HTTP and methods.


There are various signs that could indicate how the server is having problems. Error 503 service is unavailable is just an indication of a much bigger problem. Some of the symptoms are as follows:

  •         Windows runs very slowly and also responds slowly towards any mouse or keyboard input.
  •         Also, the computer can ‘freeze’ a couple of times when the server is being used.
  •         The error message ‘Service unavailable’ can also be displayed.
  •         It is possible that a malicious virus or extended program has attacked browser related files.
  •         The error 503 is no longer limited to one page. All or majority of the web pages are showing this error.
  •         Corruption in Windows registry due to the uninstalling or malfunction of any Windows related software.


This problem is related to the website’s server so we will have to deal with it and there is a low possibility that your computer has some issues in it. Nonetheless, you can try the following solutions that are likely to fix the issue.

Before delving into extensive steps and procedures, there are a few simple and easy steps you can follow to solve the 503 error.

1.Reload URL:

  •         You can rerun the URL from the address bar.
  •         Click the Reload or Refresh button. You can also do this by pressing F5.

This step is essential because sometimes the 503 service unavailable error is temporary and it would only require you to reload the page.

Other steps are as follows:

2.Restarting your router or modem:

By restarting your router or modem, you can fix the 503 error within seconds. You will also have to restart your computer this should fix any issue related to the DNS server configurations on your server. This restart will remove any issues and will run all the websites smoothly.


You can always try to reset the system for a few minutes and then, come back later. It is possible that the system is showing this error because of traffic on the web pages. A good ten minutes would suffice for reloading the page again successfully. You can read further about making browser faster and efficient.

General troubleshooting tips:

There are also some every common and widely used troubleshooting tips that can be adopted when you are faced with errors between 500 and 590. Some of these are as follows:

  •         Refresh the browser after making server changes. This usually occurs when servers are tested in a web browser.
  •         Also, to know more about how the server is handling the requests you can verify the server logs for more details.
  •         It is also possible that web servers like Apache or Nginx can produce two files like access.log and error.log that can be scanned for solving this issue.
  •         If the server is not under maintenance, this shows that the server does not have enough CPU or memory resources to handle all of the incoming requests. This could also mean that the webserver needs to be configured to allow more users, threads, or processes.


These tips will surely let you solve your own problems regarding the http errors. If you want to read more about other http errors, refer to my website page on the Ultimate HTTP Error Code List for further details and information and solutions about other errors.

Also, most of these solutions should help you resolve your issue but in the unlikely event that they don’t remember Google is your friend. Try to find a friend or public place with internet access, do searches on the error codes that keep popping up.

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Last but not least, consult your tech friends. If any of the above solutions don’t work, or you just can’t get the information that you need, they may have run into a similar situation at one time or another and can guide you in the right direction.

If you are facing any other http related errors, you can consult this category from the ErrorCodesPro website so you can easily find solutions to your error related woes within minutes!

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