hppldcoi.dll is an HP printer and scanner driver component, not a normal Windows file. When Windows reports that hppldcoi.dll is missing, was not found, or could not be loaded, the safest fix is to repair or reinstall the complete HP driver package rather than download the DLL separately.
hppldcoi.dll identity
| Property | Verified information |
|---|---|
| File name | hppldcoi.dll |
| Description | Preload Driver CoInstaller |
| Publisher | Hewlett-Packard |
| Category | Hardware driver |
| Common hardware relationship | Older HP printers and multifunction printer/scanner devices |
| Communication technology | USB DOT4 driver packages |
| Commonly listed build | 32-bit version 2.1.2.52, approximately 0.36 MB |
The version and size are not universal. Different HP products and driver packages can contain different builds, including 32-bit and 64-bit variants.
HP driver information registers the file as a preload driver co-installer, commonly alongside components such as Dot4.sys, Dot4usb.sys, Dot4Scan.sys, difxapi.dll, and PortChanger.exe. This means the file normally works as part of an INF-based printer-driver installation.
It is not a Windows runtime, DirectX component, Visual C++ redistributable, or .NET file.
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What causes the hppldcoi.dll error
The error usually appears when an HP device is being installed, reconnected, used for printing, or accessed through scanning software. Common causes include:
| Cause | What it means | Best response |
|---|---|---|
| Incomplete HP installation | The package was interrupted or only partly installed | Reinstall the complete model-specific driver |
| Old DOT4 driver | An older USB HP device needs a package Windows did not restore | Install the correct HP driver or DOT4 package |
| Incorrect architecture | A 32-bit and 64-bit package were mixed | Confirm Windows system type and reinstall |
| Antivirus quarantine | Security software removed or isolated the file | Check protection history, then repair the HP package |
| Damaged driver records | Windows driver-store or system files are damaged | Repair Windows after reinstalling the HP driver |
| Leftover HP entry | Old software still tries to load the file | Remove obsolete HP software and startup references |
| Malware impersonation | An unrelated program uses the same filename | Verify the file path, publisher, and calling program |
A message stating that the “specified module could not be found” does not always mean the DLL itself is absent. It can also indicate that a related dependency or driver component is missing.
Fix 1: Reinstall the complete HP printer or scanner driver
This is the most likely solution when the error appears while installing, printing, or scanning.
1. Identify the exact HP model
Look at the label on the printer or scanner. If Windows still detects it:
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- Select Settings.
- Open Bluetooth & devices.
- Select Printers & scanners.
- Choose the HP device.
- Note the complete model name.
For older devices, the model number may be printed on the front panel or rear label. Do not choose a similar model merely because its name looks close.
2. Remove the broken printer entry
- Open Settings.
- Select Bluetooth & devices.
- Open Printers & scanners.
- Select the affected HP printer.
- Click Remove.
- Confirm the removal.
On Windows 10, open Settings > Devices > Printers & scanners, select the printer, and choose Remove device.
If the printer is not listed, continue with Device Manager:
- Right-click Start.
- Select Device Manager.
- Expand Printers, Print queues, Imaging devices, and Universal Serial Bus controllers.
- Look for the HP device or an entry with a warning icon.
- Right-click it and select Uninstall device.
- If Windows offers Attempt to remove the driver for this device, select it.
- Click Uninstall.
- Restart Windows.
Do not remove unrelated USB controllers or devices simply because they have similar names.
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3. Download the model-specific package
Use the official HP Support site and search for the exact product model. Select the Windows version shown on your computer and download the complete printer or scanner driver package.
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Avoid choosing a generic DLL, a third-party driver bundle, or a package intended for a different model. For older USB DOT4 hardware, HP may provide a separate package named Dot4x32.msi or Dot4x64.msi.
Run the downloaded HP installer as follows:
- Disconnect the USB cable if the installer requests it.
- Right-click the HP installer.
- Select Run as administrator.
- Follow the installation prompts.
- Connect the device only when prompted.
- Restart Windows after installation.
4. Confirm that the repair worked
Print a Windows test page:
- Open Settings.
- Select Bluetooth & devices.
- Open Printers & scanners.
- Select the HP printer.
- Choose Printer properties.
- Select Print Test Page.
For a multifunction device, open the installed HP scanning application and perform a preview scan. The repair worked if the device prints or scans without the hppldcoi.dll message.
If the installer fails again, remove the device once more and install the correct architecture package manually.
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Fix 2: Install the correct DOT4 package
Older HP LaserJet and multifunction devices may communicate through USB DOT4 rather than appearing as a basic USB printer. HP documents separate packages named:
Dot4x32.msifor 32-bit WindowsDot4x64.msifor 64-bit Windows
Check whether Windows is 32-bit or 64-bit
On Windows 11:
- Open Settings.
- Select System.
- Select About.
- Find System type.
On Windows 10:
- Open Settings.
- Select System.
- Select About.
- Check System type.
Choose the package matching the installed Windows architecture. Do not select a 32-bit file just because one public listing identifies hppldcoi.dll as 32-bit. The file inside a particular driver package must match that package and device installation.
After downloading the correct HP package:
- Right-click the MSI file.
- Select Install.
- Approve the administrator prompt.
- Complete the wizard.
- Restart Windows.
- Reconnect the HP device.
- Test printing or scanning.
If HP does not provide a DOT4 package for your Windows release, use the complete model-specific driver instead. An older printer may not have a supported package for every current Windows version.
Fix 3: Check Windows Security quarantine
A security product may have isolated a driver file. This is possible, but it is not established as a common cause for hppldcoi.dll.
Check Windows Security
- Open Start.
- Type Windows Security.
- Open the application.
- Select Virus & threat protection.
- Select Protection history.
- Look for an event involving
hppldcoi.dllor the HP installer.
Do not restore the file automatically. First check whether:
- the file came from the official HP installation package;
- the file is located in an HP driver directory;
- the file has a valid Hewlett-Packard digital signature;
- the detection identifies the same file that Windows is trying to load.
If the file is legitimate, repair or reinstall the complete HP package instead of restoring only the DLL. Do not create a permanent antivirus exclusion merely because Windows reports a missing file.
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Fix 4: Verify the file and its calling program
A file named hppldcoi.dll is not automatically genuine. Malware can use a familiar filename.
Check the location:
- Press Ctrl + Shift + Esc to open Task Manager.
- Select the Details tab.
- Right-click a suspicious process.
- Select Open file location.
- Right-click the related file and select Properties.
- Open the Digital Signatures tab.
A legitimate copy should be associated with an HP driver installation and should have a plausible path and publisher. Be cautious if the file is:
- inside a temporary download folder;
- in an unrelated game or application folder;
- loaded by an unknown executable;
- unsigned when the driver package should provide a signed file;
- accompanied by suspicious startup behavior.
If an unknown program requests the DLL, investigate that program before restoring anything. Run a full scan with Windows Security and remove software you do not recognize.
Fix 5: Repair Windows components with DISM and SFC
Use these commands when several drivers or Windows components are failing, or when the HP installer reports broader system errors. They are secondary repairs, not substitutes for installing the correct HP package.
Run DISM
- Right-click Start.
- Select Terminal (Admin) or Command Prompt (Admin).
- Select Yes at the User Account Control prompt.
- Enter:
DISM.exe /Online /Cleanup-Image /RestoreHealth
- Press Enter.
- Wait for the operation to complete.
- Restart Windows.
The command repairs the Windows component store. It may take time and can appear to pause.
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After restarting:
- Open Terminal (Admin) again.
- Enter:
sfc /scannow
- Press Enter.
- Wait until verification reaches 100 percent.
- Restart Windows again.
- Retry the HP driver installation.
SFC is useful for protected Windows system files. It does not replace a missing model-specific HP driver package, so reinstall the HP driver if the DLL error remains.
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Fix 6: Remove leftover HP software and driver entries
If the error appears during startup but no HP printer or scanner is connected, an old HP utility, scheduled task, or driver reference may still be calling the file.
Uninstall obsolete HP applications
- Open Settings.
- Select Apps.
- Select Installed apps.
- Search for HP.
- Uninstall software belonging to a printer or scanner you no longer use.
- Restart Windows.
On Windows 10, use Settings > Apps > Apps & features.
Do not remove HP software that belongs to hardware you still need without first confirming its purpose.
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Check startup programs
- Press Ctrl + Shift + Esc.
- Select Startup apps.
- Look for an obsolete HP utility.
- Select it.
- Click Disable.
- Restart Windows.
If the message remains, check Event Viewer:
- Right-click Start.
- Select Event Viewer.
- Open Windows Logs > Application and Windows Logs > System.
- Look for an event at the time the error appears.
- Note the executable or service named in the event.
You can also inspect scheduled tasks, but avoid deleting entries based only on a familiar-looking name. Remove the associated HP application through Settings whenever possible.
Fix 7: Refresh the print queue
A damaged printer queue can prevent a repaired driver from loading correctly.
- Press Windows key + R.
- Type:
services.msc
- Press Enter.
- Find Print Spooler.
- Right-click it and select Stop.
- Open File Explorer.
- Go to:
C:WindowsSystem32spoolPRINTERS
- Delete the files inside this folder, not the folder itself.
- Return to the Services window.
- Right-click Print Spooler.
- Select Start.
- Restart Windows.
- Reinstall the HP driver.
You may need administrator permission to clear the queue.
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Do not begin with:
regsvr32 hppldcoi.dll
hppldcoi.dll is a driver co-installer referenced by the HP printer-driver INF. It is not normally an independently registered COM component. Running regsvr32 may produce an entry-point error, report that the module could not be loaded, or change nothing.
regsvr32 is appropriate only when the software manufacturer specifically instructs you to register a DLL or ActiveX component. A missing driver co-installer should be restored through the complete driver installation.
What not to do
Do not download an isolated copy of hppldcoi.dll from a random DLL website. The file may contain malware, belong to the wrong HP package, use the wrong architecture, have a different version, or fail because other driver files and INF records are also missing.
Do not copy the file manually into:
C:WindowsSystem32
or:
C:WindowsSysWOW64
Do not copy a 32-bit file over a 64-bit file, and do not assume that a file found in one HP package is suitable for every HP printer.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesDo not install Visual C++, DirectX, or .NET solely because this filename appears. There is no evidence that hppldcoi.dll belongs to those runtimes.
If the HP device is discontinued
An old printer may still work if HP provides a compatible driver for your Windows release, but support pages may list only older operating systems. If no current driver is offered:
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- Check Windows Update for an available printer driver.
- Check Settings > Bluetooth & devices > Printers & scanners > Add device.
- Try the model-specific HP package intended for your installed Windows version.
- Confirm whether printing works with a basic Windows driver.
- Keep the device disconnected until the installer requests it.
If the manufacturer does not provide a compatible package, forcing a different model’s driver can create more errors. Replace the driver only with a package that explicitly supports the device.
Frequently asked questions
Is hppldcoi.dll a Windows file?
No. It is associated with Hewlett-Packard printer and scanner driver packages, particularly older USB DOT4 devices.
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Is hppldcoi.dll a virus?
The filename alone cannot prove that. Verify its location, digital signature, associated HP installation, and calling executable. A copy requested by an unknown program should be investigated rather than restored blindly.
Should I download the DLL by itself?
No. The file belongs to a complete HP driver package and may depend on matching INF records, catalog signatures, architecture, and other DOT4 components.
Should I put it in System32?
No. Let the official HP installer and Windows driver store place the file where the package requires it.
Does the file have only one version?
No. Public metadata lists a commonly seen 32-bit build as version 2.1.2.52 and approximately 0.36 MB, but other driver packages can contain different builds and architectures.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Repair Windows errors before they cause bigger problems3Scan for outdated or missing drivers - takes under a minuteCan SFC restore it?
SFC repairs protected Windows system files. It may help with broader Windows corruption, but it is not the primary way to restore an HP driver co-installer.
Why does the message appear when no printer is connected?
An old HP startup item, scheduled task, service, or driver entry may still be attempting to load the file. Remove obsolete HP software and identify the calling program through Task Manager or Event Viewer.
What if reinstalling the HP driver does not work?
Confirm the Windows architecture, install the correct model package, check antivirus quarantine, run DISM followed by SFC, refresh the print queue, and inspect the exact executable named by the error. If that executable is not part of HP software, investigate it separately.
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