To modify the hosts file in the Windows system, first you need to locate its location, that is, C:\Windows\System32\drivers\etc\, which can be opened quickly by running notepad with path; secondly, editing with administrator privileges, otherwise the modification cannot be saved; the basic format of the hosts file is "IP address domain name", which can be used to block websites, local tests, etc.; when editing, you should avoid deleting the original content, one rule per line, and you can add comments by #; if the modification does not take effect, you need to execute ipconfig /flushdns to refresh the DNS cache.

Modifying the hosts file in Windows system is mainly used to block certain websites, speed up domain name resolution, or conduct local testing. This file is located in the system directory, and editing it requires certain permissions and operation skills.

Find the location of the hosts file

The hosts file is usually located in C:\Windows\System32\drivers\etc\ directory.
Although the path does not seem complicated, many users will get stuck when they first look for it, because the "etc" folder is not as intuitive as ordinary system folders. You can quickly locate by:

• Press Win R to open the run window, enter notepad C:\Windows\System32\drivers\etc\hosts , and press Enter.
• If the prompt does not have permission, it means that you also need administrator permissions to open or edit.

Edit hosts files with administrator permissions

Double-clicking to open the hosts file directly may fail because it is a protected system file. You need to run a text editor as an administrator to modify it:

1. Find the Notepad program and right-click to select "Run as administrator".
2. Click File > Open in Notepad and navigate to C:\Windows\System32\drivers\etc\ path.
3. Select "All Files" from the File Type drop-down menu, then select the hosts file and open.
4. After editing is completed, save it.

Note: Some antivirus software or system policies may prevent you from modifying the hosts file. At this time, you need to temporarily close the relevant protection or contact the system administrator.

Modify common uses and formats of hosts

The basic format of the hosts file is "IP address domain name". For example:

 127.0.0.1 localhost

Common usage scenarios include:

• Block ads or malicious websites : Point some ad servers to locally, such as:

   127.0.0.1 ad.server.com

• Local development test : Point a domain name to the local server for easy debugging:

   127.0.0.1 mysite.local

A few points to note when modifying:

• Do not delete the original content, especially localhost line.
• There is a rule for each line, no blank lines or duplication.
• Comments can be started with # and written at the beginning of the line.

How will it take effect after the modification?

After saving the hosts file, it will take effect immediately in most cases. But sometimes the DNS cache may need to be refreshed:

• Open a command prompt (CMD) and enter:

   ipconfig /flushdns

• Enter to perform, which ensures that the system reloads the latest hosts settings.

If you modify hosts but don't see the effect, it is likely that it is because the cache has not been cleared yet.

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Basically all this is it. The whole process is not complicated but there are many things that are prone to errors, especially permissions and saving issues. As long as you follow the steps, it can usually be completed smoothly.

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