How to fix "BITS service failed to start. Error 0x80004015" in Windows?

The BITS service failed to start with error 0x80004015 is an Event Viewer entry from the BITS client, Event ID 16392. Often BITS runs fine a moment later and nothing is broken. If BITS stays stopped and updates fail, start it by hand to see the real error, then fix that.

Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.

What "The BITS service failed to start. Error 0x80004015" means

BITS, the Background Intelligent Transfer Service, downloads files in the background with idle network bandwidth. Windows Update is its best known user. Programs do not call the service directly: a small client part in the program's own process connects to it. When that connection fails, the client writes Event ID 16392 to the log with the error it got back.

0x80004015 is a COM error, not a BITS error. The Windows SDK names it CO_E_WRONG_SERVER_IDENTITY: the class is set to run as a different security identity than the caller. We could not find a Microsoft page that explains it for BITS, so read it as "the program could not reach BITS at that moment", not as proof that BITS is broken.

How the entry looks in Event Viewer

Source:   Microsoft-Windows-Bits-Client
Event ID: 16392
Level:    Error
The BITS service failed to start. Error 0x80004015.

Why the BITS service fails to start, most common cause first

Most often there is no fault: a program asked for BITS while Windows was still starting or shutting down, and the next try worked. The causes below matter only when BITS really does not run.

How to fix "The BITS service failed to start. Error 0x80004015"

Fix 1 tells you in two minutes whether anything needs repair and, if so, which error BITS really has. The table sends you to the fix for that error.

Fix 1. Check BITS with sc query and start it with net start

2 minutesNo riskEveryone who sees the 0x80004015 entry, before changing anything.

The log entry says that one program could not reach BITS once. sc query shows whether the service is running now, and starting it by hand makes Windows show the error that really stops it.

1. Type cmd in search, right-click Command Prompt and select Run as administrator.
2. Run sc query bits and look at the STATE line.
3. If it shows 4 RUNNING, BITS works. Go to Settings > Windows Update and select Check for updates.
4. If it shows 1 STOPPED, run net start bits.
5. If BITS starts, check for updates as in step 3.
6. If net start bits shows "System error" with a number, write the number down and use the table above.

Command Prompt as administrator

sc query bits
net start bits

• In PowerShell or Terminal, type sc.exe query bits. In PowerShell, sc is a short name for another command.
• "The requested service has already been started" means BITS is running. That is the result you want.
• STOPPED with no error is normal when no program needs BITS. With a Manual startup type, Windows starts it when a download begins.

Fix 2. Set the BITS startup type back to Manual

5 minutesLow risknet start bits answered system error 1058, or Services shows Disabled for Background Intelligent Transfer Service.

A disabled service can never start, so every program that asks for BITS fails. Microsoft's "Issues with BITS" page lists ERROR_SERVICE_DISABLED (0x80070422) as a start error with one fix: enable the service. Microsoft's service list gives Manual as the default.

1. Press Win + R, type services.msc and press Enter.
2. Double-click Background Intelligent Transfer Service.
3. Set Startup type to Manual. Automatic (Delayed Start) also works.
4. Select Apply, then Start, and wait until Service status shows Running.
5. Select OK and check for updates.

The same from an administrator Command Prompt, with a space after start=: sc config bits start= demand, then net start bits. Opening Services and changing a startup type: Check and restart Windows services

Fix 3. Start the services BITS depends on: RPC and COM+ Event System

5 minutesLow risknet start bits answered system error 1068, "The dependency service or group failed to start".

BITS starts only after its dependencies run. Microsoft lists them as RpcSs (Remote Procedure Call) and EventSystem (COM+ Event System). If one is stopped or the list is wrong, BITS cannot start.

1. In an administrator Command Prompt, run sc qc bits and read the DEPENDENCIES lines. They should be RpcSs and EventSystem.
2. Run sc query EventSystem and sc query RpcSs. Both should show RUNNING.
3. If COM+ Event System is stopped, open it in Services, set Startup type to Automatic and select Start.
4. If the dependency list is wrong, run sc config bits depend= RpcSs/EventSystem.
5. Run net start bits again.

Command Prompt as administrator

sc qc bits
sc query RpcSs
sc query EventSystem
sc config EventSystem start= auto
net start EventSystem
net start bits

If COM+ Event System fails too, its own dependency is the cause. Finding it step by step: error 1068: the dependency service or group failed to start.

Fix 4. Restore the BITS Parameters key and qmgr.dll in the registry

10 minutesRead the warningnet start bits answered system error 2, "The system cannot find the file specified".

BITS runs from qmgr.dll inside a shared service host. Windows finds that file through the ServiceDll value in the BITS Parameters key. Microsoft's start error table says that when this key is missing, BITS fails with ERROR_FILE_NOT_FOUND (0x80070002).

1. Check that the file exists: in File Explorer, open C:\Windows\System32 and look for qmgr.dll. If it is missing, go to Fix 8.
2. Press Win + R, type regedit and press Enter.
3. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BITS.
4. If there is no Parameters key under BITS, right-click BITS, select New > Key and name it Parameters.
5. In Parameters, open ServiceDll, or create it with New > Expandable String Value.
6. Set its value to %SystemRoot%\System32\qmgr.dll and select OK.
7. Restart the PC and run net start bits.

The key and value Microsoft gives

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BITS\Parameters
ServiceDll  (REG_EXPAND_SZ) = %SystemRoot%\System32\qmgr.dll

Fix 5. Put back the default BITS service settings with sc config

10 minutesLow riskBITS starts and stops again, fails with an access error, or a tool changed its settings.

Microsoft's "Issues with BITS" page says BITS must run under the Local System account and gives sc commands to enter its configuration again. A changed account, program path or service type stops BITS whatever its startup type is.

1. Open Command Prompt as administrator.
2. Run the commands below one by one. Each should answer [SC] ChangeServiceConfig SUCCESS.
3. Restart the PC.
4. Run net start bits and check for updates.

Command Prompt as administrator (keep the space after each equal sign)

sc config bits obj= LocalSystem
sc config bits binpath= "%SystemRoot%\System32\svchost.exe -k netsvcs"
sc config bits depend= RpcSs/EventSystem
sc config bits start= demand
sc config bits error= normal

Fix 6. Scan for malware when BITS settings keep changing

15 to 30 minutesNo riskBITS goes back to Disabled or loses its settings after you fixed it, or other security services are off too.

BITS can download files in the background, so it is a known target for malware, and some malware turns off update services to block security updates. If something keeps changing BITS, fixing the setting again will not last.

1. Run a full scan with Windows Security, and the offline scan if the full scan finds anything.
2. Remove what it finds and restart.
3. Repeat Fix 2 or Fix 5.
4. Check after the next restart that BITS keeps its startup type.

Full and offline scan step by step: How to scan for malware with Microsoft Defender

Fix 7. Reset Windows Update components and the BITS queue

15 minutesLow riskBITS runs, but Windows Update still fails, or a program says "A new BITS job could not be created".

BITS keeps its list of downloads in qmgr*.dat files. If that queue or the Windows Update cache is damaged, BITS can run and still fail every new download. The reset stops the services, clears the queue and the cache, and starts them again.

1. Open Command Prompt as administrator. Type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.
2. Stop the update services. Type the commands below and press Enter after each one. If Windows says that other services depend on Cryptographic Services, it stops them too. A message that a service is not started is fine.

   net stop wuauserv
   net stop bits
   net stop cryptsvc

3. Delete the download queue files. This clears the list of downloads that the Background Intelligent Transfer Service keeps. If Windows says it cannot find the files, continue.

   del "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat"

4. Rename the update cache folders. Renaming keeps a copy in case you need it; Windows creates new, empty folders when the services start again. If you get Access is denied, a service is still running: repeat the previous step.

   ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
   ren %systemroot%\System32\catroot2 catroot2.old

5. Start the services again. Type the commands below and press Enter after each one. The requested service has already been started is fine: Windows started it on its own.

   net start cryptsvc
   net start bits
   net start wuauserv

6. Restart and check for updates. Restart the PC. Then select Start > Settings > Windows Update > Check for updates. The first check can take longer than usual because everything is downloaded again.

These steps were written for Windows 11 and Windows 10 (the steps are the same). The full page with the other versions and what each result means: Reset Windows Update components

Fix 8. Repair Windows system files with DISM and SFC

15 to 30 minutesNo riskSeveral Windows services fail, qmgr.dll is missing, or Remote Procedure Call is not running.

When qmgr.dll or the COM files BITS uses are damaged, BITS fails whatever its settings are. DISM repairs the store of Windows components, and SFC puts damaged system files back from it.

1. Open an elevated command window. Right-click Start and select Terminal (Admin), or type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.
2. Run DISM first. Type the command below and press Enter. DISM downloads clean copies of damaged components from Windows Update, so it can take several minutes. Wait until it says The operation completed successfully.

   DISM.exe /Online /Cleanup-Image /RestoreHealth

3. Run System File Checker. In the same window, type the command below and press Enter. Do not close the window until the verification reaches 100%.

   sfc /scannow

4. Read the result and restart. Compare the last message with the table below this guide, then restart the PC so that repaired files are loaded.

These steps were written for Windows 11 24H2 and 25H2. The full page with the other versions and what each result means: Run DISM and SFC to repair Windows system files

Fix 9. Go back to a restore point or reinstall Windows over itself

30 to 90 minutesRead the warningNothing above worked, or BITS is not installed at all (sc query bits answers 1060).

System Restore puts back the service settings of an earlier day. A repair install replaces every Windows file and restores the default Windows services, BITS included, while it keeps your files and apps.

1. Press Win + R, type rstrui and press Enter.
2. Choose a restore point from before BITS stopped working and select Scan for affected programs.
3. Select Next and Finish, and let the PC restart.
4. With no usable restore point, reinstall Windows while you keep your files and apps.

System Restore step by step: Undo recent changes with System Restore Repair install: Reinstall Windows without losing files

If BITS still fails to start: what to read and what to collect

With this error the useful facts are whether BITS runs and which error it gives when you start it by hand. Collect these before you post in Microsoft's forum or contact support.

• The output of sc query bits, sc qc bits and net start bits.
• The System log. In Event Viewer, open Windows Logs > System and filter by the sources Bits-Client and Service Control Manager. Note the time of the 16392 entries and what is logged right next to them.
• The BITS log. Open Applications and Services Logs > Microsoft > Windows > Bits-Client > Operational to see which program's download failed.
• What changed. Run perfmon /rel to open Reliability Monitor, which lists installs, updates and removals by day.
• Your Windows version and build. Press Win + R, type winver and note both.

Windows 10 left support on 14 October 2025. A Windows 10 PC that cannot download updates gets no security fixes either way, so a repair install is a good moment to plan the move to Windows 11.

How to keep BITS working

Frequently asked questions

What does "The BITS service failed to start. Error 0x80004015" mean?

It means a program tried to use the Background Intelligent Transfer Service and the connection to it failed at that moment. The BITS client writes it to the log as Event ID 16392. The code 0x80004015 is a COM error that the Windows SDK names CO_E_WRONG_SERVER_IDENTITY. Microsoft does not explain it for BITS. Check with sc query bits whether BITS runs now. If it does and updates install, the entry was a one-off.

Is Event ID 16392 from Bits-Client harmful?

The entry itself does no harm. It only records that one connection to BITS failed. It matters when BITS stays stopped, because then Windows Update and other programs cannot download in the background. Run sc query bits and net start bits in an administrator Command Prompt, and check for updates in Settings. If both work, you can ignore the entry. If BITS does not start, the error number net start gives leads to the right fix.

How do I start or restart BITS?

Open Command Prompt as administrator and run net start bits to start it, or net stop bits and then net start bits to restart it. Microsoft's own page uses sc stop bits and sc start bits, which do the same. In Services, find Background Intelligent Transfer Service, right-click it and select Start or Restart. If Windows says the requested service has already been started, BITS is running.

What is the default startup type of BITS?

Microsoft's list of Windows services gives Manual as the default startup type of the Background Intelligent Transfer Service. Windows starts it when a program begins a download, and it can show as stopped the rest of the time. Automatic (Delayed Start) also works. Disabled stops Windows Update from downloading updates, so do not choose it. The service runs under the Local System account and depends on Remote Procedure Call and COM+ Event System.

What does "A new BITS job could not be created" mean?

A program that uses BITS, such as an updater, could not add a new download. Most often BITS is stopped or disabled, so start with Fix 1 and Fix 2. If BITS runs and the message stays, the download queue may be damaged: the Windows Update reset in Fix 7 clears the qmgr data files where BITS keeps its jobs. If only one program shows the message, repair or reinstall that program.

Is there a BITS repair tool for Windows 10 and Windows 11?

Windows has no separate BITS repair program. Some versions list a Background Intelligent Transfer Service troubleshooter under Settings > System > Troubleshoot > Other troubleshooters, and Windows 10 has it under Troubleshoot in Control Panel. It checks the same things as Fix 1 to Fix 3. The commands in Fix 1 and Fix 5 do the same job and show you what they changed. Avoid download sites that offer a BITS fix tool.

Why does BITS keep stopping?

With a Manual startup type, BITS stops by itself when no download needs it, which is normal. If it stops while Windows Update is downloading, or its startup type changes back to Disabled, something changes it. Common reasons are tweak tools, "speed up Windows" scripts and malware. Set it back with Fix 2, then run the malware scan in Fix 6 and check whether the setting stays after a restart.

The Russian message "Не удалось запустить службу BITS. Ошибка: 0x80004015" is on my PC. Is it the same?

Yes. It is the same Event ID 16392 entry on a Russian copy of Windows, and the fixes are the same. The related message "Служба BITS завершена из-за ошибки: Не удается найти указанный файл" means the BITS service stopped with error 2, the file cannot be found. Microsoft ties that to a missing Parameters key, which Fix 4 restores.

I searched for "bit data failed to load". Is that this error?

No. This page is about BITS, the Windows download service, and its Event ID 16392 entry. "Bit data failed to load" is a different message that some programs and games show when their own data does not load. It has nothing to do with BITS. Search for the full message together with the name of the program that shows it.

Does this error appear on Windows 11 and Windows 10?

Yes. The Event ID 16392 entry and the BITS settings are the same on Windows 11 and Windows 10, and so are the fixes on this page. Older logs from Windows 7 show the same text. Windows 10 left support on 14 October 2025, so a Windows 10 PC no longer gets security updates even when BITS works.