What should I check first when I see symptoms of a DNS error?

First, proceed with the ‘Compare on other sites and devices’ step. Distinguish whether it is a problem with the site itself or with the PC's DNS/browser. We recommend that you avoid changing multiple settings at once and check to see if your symptoms change after each step.

How do I check for a possible cause ‘DNS server response problem’?

If there is no change in the first step, compare in order through ‘Check browser cache and extensions’. If symptoms disappear immediately after certain actions or the conditions for their occurrence change, this can be an important clue in narrowing down the cause.

Internet connection, but site address not opening due to DNS: When do I need a professional check?

Even if you follow the above solution steps in order, if DNS error symptoms repeat or hardware abnormalities such as a burning smell, abnormal noise, overheating, or failure to recognize parts appear together, we recommend backing up important data and performing a professional inspection.

PC FIX

Computer Troubleshooting Guide

Internet

The Internet is connected, but the site address cannot be opened due to DNS.

If “DNS errors” occur repeatedly, it is better to narrow the scope to DNS server response issues and DNS cache rather than changing several settings at once. First, determine whether the Internet itself was disconnected or just name resolution failed, and then check your DNS settings.

Solving Order
We've organized the methods starting with the simplest and least expensive ones. Please check the solutions one by one, starting from the top.

Do you have these symptoms?

DNS error
Server IP address not found
DNS_PROBE
Only the address doesn't open

main causes

DNS server response issues
DNS cache
VPN·Security Program

How to solve

Please check them in order from the top. If the issue is resolved, you do not need to proceed to the next step.

Compare on other sites and devices

Distinguish whether it is a problem with the site itself or with the PC's DNS/browser.

Difficulty Easy time 5 minutes cost 0 won

1Try opening several sites.
2Check if the site opens on phones on the same network.
3Check if the problem is only in one browser.

confirmation point

See if your “DNS Error” symptoms decrease or disappear after these steps. If there is no change, check for possible DNS server response issues in the next step.

Check your browser cache and extensions

If it's only a problem with a specific browser, it may be more on the browser side than DNS.

Difficulty Easy time 5-10 minutes cost 0 won

1Connect from a secret/private window.
2Turn off the extension briefly.
3Check if it's the same in other browsers.

Reset DNS cache

You can remove outdated or incorrect DNS cache.

Difficulty Moderate time 3 minutes cost 0 won

1Open an administrator terminal.
2Run ipconfig /flushdns.
3Close your browser completely and reopen it.

Compare changing DNS servers to automatic or another trusted server

You can check for current DNS server failures or response delays.

Difficulty Moderate time 10 minutes cost 0 won

1Check whether your current DNS is manual or automatic.
2Temporarily change to Automatic or Public Trusted DNS to compare.
3Once the problem is resolved, check the existing router/ISP DNS status.

Check VPN, proxy, and security filters

Programs that intercept DNS requests can block certain sites.

Difficulty Moderate time 10-20 minutes cost 0 won

1Temporarily turn off your VPN and proxy.
2If it is a company or school network, check whether the site is blocked by policy.
3Also check your security program's web filters.

Frequently Asked Questions

We've put together a list of things we frequently check regarding this issue.

Related issues

If the symptoms do not match exactly, please check the issue below.

Internet

Issue with only certain websites not opening

If the current symptom is closer to “only a specific site does not open,” first check the DNS/browser cache, site, or ISP path. First, determine whether the Internet itself was disconnected or just name resolution failed, and then check your DNS settings.

View solutions →

Internet

Speed tests are normal, but web browsing is slow

If the current symptom is closer to “only the browser is slow,” check extensions, DNS, and cache first. First, determine whether the Internet itself was disconnected or just name resolution failed, and then check your DNS settings.

View solutions →

Internet

Computer suddenly unable to connect to internet

When troubleshooting a computer that suddenly fails to connect to the Internet, it is important to rule out the causes one at a time. Based on the “No Internet” symptom, check the router/modem or ISP problem and the network adapter/IP/DNS settings, then proceed to the next step. Compare with other devices and wired connections to narrow down where the problem occurs: PC, router, or ISP.

View solutions →

Internet

Internet not working after Windows update

If “No internet after update” repeats, it is better to narrow the scope to updated network drivers and changes to TCP/IP settings rather than changing several settings at once. Compare with other devices and wired connections to narrow down where the problem occurs: PC, router, or ISP.

View solutions →

Look for other symptoms too

If you enter the symptoms you are currently seeing in the PC FIX search box, we will find the related problem.

Search for other issues →