Windows Host File Problems

Every domain name is linked to an IP address, which is how you find the website you are seeking. Because the host file can be used to link IP address to domain names, it can cause as many problems as it solves.

Malware

Certain malware--a shortening of the phrase "malicious software"--modifies the hosts file to redirect from popular websites, such as Google or Microsoft, to more questionable websites. There are certain programs that can detect such redirects; additionally, if you suspect tampering, you can check your hosts file manually from C:\System32\Drivers\Etc\Host.

Out-of-Date Addresses

IP addresses can change; if you do not keep your hosts file up to date, this can cause your browser to fail to connect to websites. Check occasionally to make sure that all IP addresses and domains are up to date.

Syntax

Using "http://" or any other symbols outside of letters, numbers, periods and spaces, will cause errors in the host file. There must be one space between an IP address and a domain name. Additionally, if an entry as a pound sign in front of it, this disables it; you can re-enable it by removing the pound sign.

Copy Errors

If you create a host file in another folder and copy it to the proper directory, or rename the hosts file, Windows may not recognize it and problems may result. Windows has issued a hot fix if you find yourself with this problem.

References

• Bleeping Computer: The Hosts File and what it can do for you
• Computer Education: Using the Windows Hosts File

Resources

• Microsoft Support: The Hosts File Does Not Reflect Changes If You Alter It by Renaming or Copying