How to resolve Error 26 in SQL Server?

Question

We're accessing our database with our server (another computer). Before, I'm able to connect with it but it suddenly stop and now I cant connect and I encounter this error which is error 26 Locating Server.

Others can connect with our server. I don't know what I've done or what I've change with my machine that causes me to not connect with our server. Can anyone suggest what should I do?

I'm using SQL Server 2008 R2.

By the way, I can access our server using Remote Desktop Connection but when I'm connecting using SQL Server 2008 R2, I really can't connect. I'm using the right server name but it doesn't work.

I've tried connecting to other server and It do work. What should I do? I don't know why it happened.

Answer 1

Try flushing your DNS.

Open a DOS window to do this.

1. Click Start Button
2. Type CMD and press enter

3. Type this into the black window that appears: ipconfig /flushdns and press enter you should see:

   Windows IP Configuration

   Successfully flushed the DNS Resolver Cache.

See if this does not correct your issue.

Answer 2

I tried using the (IP address of the server)\SQLEXPRESS and it do work. Yet I still dont know why It cant access the instance name of the server.

Answer 3

Be sure that SQL Server service is running. If SQL Server service is not running you can run it by:

1. Opening Run Window (WINDOW+R) and type services.msc.
2. Find the SQL Server and right click on it then click start.
3. Try reconnecting again to your SQL Server

After that if it is still not running, Open your "Windows Defender Firewall with Advance Security" and add port 1433 both in inbound and outbound rules and make sure that you selected the allow connections.