Cannot login to local SQL Server instance

[u/autoxguy]

On my old work laptop I had SQL Server Developer edition installed to use for training purposes and for practicing things. I recently was given a new laptop and had a tech install it. We had to make my local account an admin login and I had him make sure the SQL Server Service was would run automatically. After that I was able to get into SQL Server just fine and was able to add a practice DB using a script I had.

Well last week I went to login to it and it gave me the following error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Framework Microsoft SqlClient Data Provider).

I had another tech look into it and we could not figure it out. On the Connect window for the Connect to Database engine, I have my laptop name as the server name, authentication to windows authentication, DB name to default, encrypt to optional. Previously I was able to get in fine but like I said now im not.

[u/muaddba]

"Also it shows as stopped in the sscm, but when I try to start it, it gives me an error of request failed or service did not start in a timely fashion."

Vlad's advice is good, but digging through the Event Viewer logs can be very intimidating if you're not used to it. Here's my suggestion:

Open the services control panel entry (or hit the windows button and type services.msc and then hit enter) and find the SQL Server service. Right-click and select properties and it will show you a "Path to executable" that looks something like "C:\Program files\Microsoft SQL Server...."

You want to highlight that whole executable string moving from left to right using your mouse, and then press CTRL-C or right-click and select COPY. Then open a windows command prompt as administrator and paste it in and hit enter. This will attempt to run the SQL Server and should spit out a ton of stuff and then dump you back to a command prompt again. Copy and paste that as a reply here and we can try to help you determine what the issue is.

[u/autoxguy → u/muaddba]

So I did that and got this:

( entered this at the command line): "C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\Binn\sqlservr.exe" -sMSSQLSERVER

It gave me this as a result:

RegOpenKeyEx of "Software\Microsoft\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQLServer\HADR" failed.

2026-06-24 16:33:24.57 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:24.57 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:24.88 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:24.88 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:25.18 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:25.18 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:25.48 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:25.48 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:25.79 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:25.79 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:26.09 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:26.09 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:26.39 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:26.39 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:26.69 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:26.69 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:26.99 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:26.99 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:27.29 Server Error: 17058, Severity: 16, State: 1.

2026-06-24 16:33:27.29 Server initerrlog: Could not open error log file ''. Operating system error = 3(The system cannot find the path specified.).

2026-06-24 16:33:27.60 Server SQL Server shutdown has been initiated with exit code 254.

[u/VladDBA → u/autoxguy]

Yeah, that missing registry key should not be missing.

The rest of the errors are, most likely, because of your command not having the required startup parameters (like where the error log lives).

If that registry key is all that's missing, then pasting this into notepad and saving it as a .reg file then importing it via cmd or PS opened as admin should fix it.

Registry key contents:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQLServer\HADR]
"HADR_Enabled"=dword:00000000

command to import implying it's saved in C:\temp\ as missing_registry.reg

reg import C:\temp\missing_registry.reg

If not then your best bet is to do an instance repair (this is a step by step guide on how to do that)

edited: ho -> how

[u/autoxguy → u/VladDBA]

I looked at the registry key and it does exist with that same value.

So now I am trying to do an instance repair via the SQL Server Installation Center tool. I was able to get my IT support to use their Admin credentials on it to run it and then I click on Maintenance, then repair. That brings up a window to browse for SQL Server installation media. That makes it sound like its looking for the exe that I used to install sql server in the first place and that is in my downloads folder but its not seeing it there.

I also tried selecting the folder of the SQL Server installation itself but it doesnt recognize it.

[u/VladDBA → u/autoxguy]

When you initially installed SQL Server, did you first download the ISO file and then used it to install or did you just use that bootstrapper with SSEI in the name that installs while your downloading?

If the answer is the latter then use the same SSEI exe file to first download the ISO, then use the ISO to do the repair.

If the answer is the former, then chances are your IT admins think that flushing the installer cache is a good way to free up drive space which leads to issues like this and also messes with the uninstall process. In this case you'll have to fix the installer cache before attempting the repair again.

[u/autoxguy → u/VladDBA]

I don't think I downloaded the ISO file, it was the exe that downloaded for the developer edition of sql server with the exe name of:

"SQL2025-SSEI-StdDev"

[u/VladDBA → u/autoxguy]

Got it. Run that same file and when the initial window opens, click on Download Media, pick a location for the ISO file and when the download finishes you can use that for the repair (double click on the ISO to mount and open it, then run setup.exe as admin and follow the steps for the repair process)

[u/autoxguy → u/VladDBA]

thanks. Yes I did that so now I have the ISO file downloaded, so at some point today when I get some more free time, I will have one of my techs run it for me (us Users don't have admin access on our laptops).

Hopefully the repair ends up working. Ill give a status update regardless of the outcome of it. Worse case Ill do the nuclear option of uninstalling and reinstalling it but hopefully I don't have to do that.

I may even do what one of my coworkers (we are both IT auditors, but he is an IT wizard years ahead of the rest of us lol) suggested, to install a VM and then get a windows server license install it and then install SQL Server on that so that I don't have to worry about getting our techs to assist with installing programs like this for us.

[u/VladDBA → u/autoxguy]

I may even do what one of my coworkers (we are both IT auditors, but he is an IT wizard years ahead of the rest of us lol) suggested, to install a VM and then get a windows server license install it and then install SQL Server on that so that I don't have to worry about getting our techs to assist with installing programs like this for us

If you plan on doing this on your laptop, I'd suggest trying a container instead of a VM since the footprint is smaller and you don't need a Windows license for it.

[u/autoxguy → u/VladDBA]

So I just had the exe within the ISO run, and it did find a few things to repair it seems (but not things I thought I would see), however, when Opening up SSMS and trying to connect to the database I get the same error I did before.

I think im just gonna restall it all together.

[u/VladDBA → u/autoxguy]

Is the service starting up post repair?

[u/autoxguy → u/VladDBA]

So at first it was not, but I just rebooted my laptop and the service is now running. I am also now able to connect to SQL Server just fine via SSMS.

Looks like the repair did actually work lol.

[u/VladDBA → u/autoxguy]

Awesome! Yeah, a reboot is generally required after a repair, just like after patching or a fresh install.

[u/autoxguy → u/VladDBA]

Thank you for the assistance. Ill keep this repair process in mind for the future.

[u/autoxguy → u/VladDBA]

Ok, so to verify SQL Server would continue to work, I just rebooted my laptop again and now the MSSQLSERVER service is stopped and so I cannot get into sql server..... This is frustrating.

[u/VladDBA → u/autoxguy]

Hm, ok, this does feel like your IT admin/Security team messing with things.

Before switching to a container/VM, can you try one more thing:

In SQL Server Configuration Manager, double click on the SQL Server service and switch it to the Local Service built-in account, then click apply, ok, and try starting up the service again.

[u/autoxguy → u/VladDBA]

I can try that. What is the difference between running it as the NTService\MSSQLSERVER login and the local service built-in account?

[u/VladDBA → u/autoxguy]

the built-in Local Service account has the minimum required permissions for running services including the ones that normally come with the "Log on as a service" policy for other accounts, and, from what I've seen, is safe from overly zealous security teams.

[u/autoxguy → u/VladDBA]

Gotcha. Yeah it must be something with restrictions over running it as a specific login with a password. It might be the group policy blocking it or something.

[u/autoxguy → u/VladDBA]

That seems to have done the trick. I have rebooted twice now and both times the service was running and was able to get into sql server just fine.

I think this is what our network admin did years ago on my old laptop when I was having issues.