Start with this diagnostic checklist
Before changing files, note:
- Which program shows the error: AutoCAD, an AutoCAD-based application, or a plug-in.
- When it appears: at startup, while opening a drawing, or when running a LISP, ARX, DBX, VBA, or ObjectDBX routine.
- Your AutoCAD release: acdb15.dll is associated with AutoCAD 2000, AutoCAD 2000i, and AutoCAD 2002.
- Your Windows architecture: the commonly reported acdb15.dll build is 32-bit, so it must match the legacy application rather than the bitness of Windows alone.
- Whether the file recently disappeared: check after an update, cleanup, antivirus scan, failed installation, or plug-in installation.
The safest first step is to repair or reinstall the specific Autodesk product that needs acdb15.dll. Do not begin by downloading a replacement DLL or copying one into System32.
What acdb15.dll is
acdb15.dll is an Autodesk ObjectDBX and AutoCAD database library. ObjectDBX provides database-object functionality used by AutoCAD and compatible RealDWG host applications.
The number 15 identifies an older AutoCAD/ObjectARX generation. AutoCAD 2000, AutoCAD 2000i, and AutoCAD 2002 are strongly associated with acdb15.dll. Later AutoCAD generations use different files, including acdb16.dll and acdb17.dll.
It is not a Windows system file. It normally belongs in an Autodesk installation or shared Autodesk directory, not in:
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →#1 Best Overall
C:WindowsSystem32
C:WindowsSysWOW64
A commonly reported catalog entry describes acdb15.dll as a 32-bit file, version 15.0.0.126, with a size of approximately 3.73 MB. Those details are third-party metadata rather than a verified Autodesk installer manifest, so they should not be used as the only test of authenticity.
The filename can also be confused with AxDb15.dll. That is a related ActiveX/ObjectDBX automation library, but it is a different file and should not be substituted for acdb15.dll.
Errors associated with acdb15.dll
You may see wording such as:
- “The program can’t start because acdb15.dll is missing from your computer.”
- “The code execution cannot proceed because acdb15.dll was not found.”
- “There was a problem starting acdb15.dll.”
- “Error loading acdb15.dll. The specified module could not be found.”
- “acdb15.dll is either not designed to run on Windows or it contains an error.”
- An AutoCAD startup failure or access-violation crash involving acdb15.dll.
“The specified module could not be found” does not always mean the named file is absent. Windows may have found acdb15.dll but failed to load another library that it depends on. Multiple copies in different folders can also cause Windows to load the wrong generation.
Fix 1: Repair the Autodesk installation
This is the most likely solution when AutoCAD stopped working after a cleanup, failed update, partial uninstall, or accidental deletion.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11- Press Windows + R.
- Type
appwiz.cpland press Enter. - Find the affected Autodesk product in Programs and Features.
- Select it and choose Uninstall/Change.
- In the Autodesk maintenance window, select Repair.
- Follow the prompts and restart Windows when finished.
- Start AutoCAD and test the action that previously produced the error.
Repair restores missing or damaged product files while retaining the existing installation where possible.
If Repair is not available or does not work:
- Return to Control Panel → Programs → Programs and Features.
- Select the Autodesk product.
- Choose Uninstall/Change.
- Select Reinstall, if the installer provides that option.
- Use the original licensed installation media or an Autodesk-provided installer.
- Restart Windows and test AutoCAD again.
For newer Autodesk products, the maintenance screen may offer only uninstall and reinstall. Do not use an installer for a different AutoCAD release. An installer for a later generation may provide acdb16.dll or another library, not the acdb15.dll required by an older plug-in.
Fix 2: Confirm that the application and plug-in match
A plug-in compiled for the AutoCAD 15.x generation can request acdb15.dll even if AutoCAD itself is installed correctly. This commonly happens when a legacy ARX, DBX, Object Enabler, LISP routine, or other extension is copied into a newer installation.
Check the following:
- Start AutoCAD without loading the affected plug-in, if possible.
- If AutoCAD opens, disable recently added extensions.
- Remove or rename the plug-in’s configuration entry temporarily.
- Restart AutoCAD.
- Reinstall a plug-in build that explicitly supports your AutoCAD release.
- If the plug-in is obsolete, leave it disabled and test the core application.
If AutoCAD starts normally but fails only when opening a particular drawing or running a routine, the plug-in is more likely to be the requester.
Do not rename another file, such as acdb16.dll, to acdb15.dll. The names represent different API generations and are not interchangeable.
Fix 3: Check whether antivirus quarantined the file
Security software may remove or quarantine a file after a scan. Quarantine is a possible cause, not proof that acdb15.dll was malicious or a false positive.
In Windows 10 or Windows 11:
- Open Start and search for Windows Security.
- Select Virus & threat protection.
- Choose Protection history.
- Review entries from the time AutoCAD stopped working.
- Open a relevant entry and examine the detected path and action.
- Restore the file only if you can establish that it came from your legitimate Autodesk installation.
After restoring a verified file, repair the Autodesk installation rather than relying on the restored copy alone.
Do not create a broad Defender exclusion for a DLL downloaded from an unknown site. If the file was obtained from random download media, remove it and reinstall the Autodesk product from legitimate installation media.
Recommended Free Tools
Fix 4: Check the expected installation path
The exact path varies by AutoCAD release and installation method. A reported AutoCAD 2002 installation used a shared Autodesk folder similar to:
C:Program FilesCommon FilesAutodesk Shared
Your installation may use a different Autodesk directory.
To investigate:
- Right-click the AutoCAD shortcut.
- Select Properties.
- Select Open File Location.
- Check the application and shared Autodesk directories.
- Search only the Autodesk installation folders for
acdb15.dll. - Do not overwrite every copy you find.
Windows normally searches the application directory and other defined locations when loading a DLL. A copy beside the application can take precedence over a copy elsewhere. Different AutoCAD generations may legitimately have separate directories, so deleting or replacing all copies can create additional failures.
Fix 5: Do not use Regsvr32 for acdb15.dll
Running this command is normally incorrect:
regsvr32 acdb15.dll
regsvr32 is intended for DLLs that provide COM self-registration entry points, including certain ActiveX controls. acdb15.dll is an AutoCAD database/runtime library loaded by the Autodesk application. It is not normally repaired by registering it.
The command may report that DllRegisterServer was not found. That does not mean Windows needs a different copy of acdb15.dll. It means the file is not designed for that registration operation.
The separate AxDb15.dll issue can involve ActiveX/ObjectDBX automation, but do not substitute AxDb15.dll for acdb15.dll or register arbitrary files without product-specific instructions.
Fix 6: Check broader Windows component corruption
Use Windows repair commands only when there are broader symptoms, such as failures in several unrelated programs, damaged Windows components, or repeated system file errors. These commands generally will not recreate acdb15.dll because it is an Autodesk file, not a protected Windows component.
Open an elevated Command Prompt:
- Open Start.
- Type Command Prompt.
- Right-click Command Prompt.
- Select Run as administrator.
- Approve the User Account Control prompt.
- Run:
DISM.exe /Online /Cleanup-image /Restorehealth
Wait for it to finish. Then run:
sfc /scannow
Microsoft documents this order in its System File Checker instructions. Restart Windows afterward and test AutoCAD.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problemsIf the commands report repaired Windows files but acdb15.dll is still missing, that result is expected. Return to the Autodesk repair or reinstall step.
Repeating SFC and DISM without knowing what changed makes diagnosis harder. Outbyte PC Repair can scan for broader Windows problems and show what it identifies before repair; its full repair capability is optional, and reinstalling the Autodesk product remains the definitive fix for an absent Autodesk DLL.
Fix 7: Update Windows, but do not expect a driver update to replace the DLL
A Windows update can improve compatibility, but it will not normally install acdb15.dll. Check for updates anyway if the system has other failures:
- Open Settings.
- Select Windows Update.
- Choose Check for updates.
- Install available updates.
- Restart the computer.
You can also check hardware drivers if AutoCAD is crashing alongside display or system instability:
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →- Right-click Start.
- Select Device Manager.
- Expand Display adapters and other relevant categories.
- Right-click the affected device.
- Choose Update driver.
- Select Search automatically for drivers.
Do not treat Device Manager as a way to repair an Autodesk DLL. Outbyte Driver Updater can reduce the work of hunting through multiple device vendors by showing outdated drivers in a scan; installing drivers remains optional and is not a substitute for repairing AutoCAD.
Fix 8: Test compatibility for legacy AutoCAD
AutoCAD 2000, 2000i, and 2002 were designed for much older Windows environments. Windows 10 and Windows 11 may run some legacy installations only with limitations, and compatibility mode is not a guaranteed DLL repair.
To test compatibility mode:
- Right-click the AutoCAD executable or shortcut.
- Select Properties.
- Open the Compatibility tab.
- Select Run this program in compatibility mode for.
- Choose an older Windows version from the list.
- Select Run this program as an administrator only if necessary.
- Click Apply, then OK.
- Start AutoCAD and test it.
If the error remains, use a properly licensed older Windows virtual machine or isolated legacy workstation where practical. Reinstalling the same obsolete release directly on a current system may restore the file while leaving the broader compatibility problem unresolved.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Fix 9: Investigate missing dependencies
If acdb15.dll exists but Windows still reports that the specified module could not be found, a dependency may be missing or incompatible.
Free tools Windows power users keep installed
One-click scans. No signup required.
Start with the complete Autodesk installation:
- Repair the Autodesk product.
- Repair or reinstall the affected plug-in.
- Restart Windows.
- Test without third-party extensions.
- Add extensions back one at a time.
A dependency inspection tool can help an experienced administrator identify which library fails to load, but do not replace dependencies at random. Installing a similarly named DLL from another AutoCAD release can make the search path conflict worse.
Why random DLL downloads are unsafe
Downloading acdb15.dll from a random DLL website is not a reliable repair. The file may:
- Belong to the wrong AutoCAD generation.
- Be the wrong architecture.
- Have been modified or bundled with malware.
- Require other Autodesk libraries that are also missing.
- Load from the wrong folder because of Windows DLL search behavior.
- Fail to restore Autodesk configuration, registry entries, licensing, or plug-ins.
Do not copy the file into System32 or SysWOW64. Do not rename another acdbXX.dll. There is no need to treat acdb15.dll as a generic Windows component.
The safe recovery sources are your own verified backup, legitimate original Autodesk installation media, an Autodesk-provided installer, or Autodesk support and account channels. Repairing or reinstalling the complete product is preferable to manual copying.
If the error still remains
Collect these details before seeking technical help:
- The complete error text.
- The program that displays it.
- The AutoCAD release.
- Windows edition and architecture.
- The full path where acdb15.dll is expected.
- Whether AutoCAD starts without the plug-in.
- Whether the failure began after an update, cleanup, antivirus action, or installation.
- The names of any ARX, DBX, LISP, VBA, or Object Enabler components involved.
Then inspect the Autodesk installation log, disable third-party plug-ins temporarily, and test with a clean user profile or clean boot. If the product is AutoCAD 2000, 2000i, or 2002 running directly on current Windows, compatibility may be the underlying problem even after the missing file is restored.
Best Value
Frequently asked questions
Is acdb15.dll a Windows file?
No. It is an Autodesk ObjectDBX and AutoCAD database library. It should not normally be copied into a Windows system folder.
Which AutoCAD versions use acdb15.dll?
The strongest association is with AutoCAD 2000, AutoCAD 2000i, and AutoCAD 2002. Later releases use other numbered acdb libraries.
Is acdb15.dll 32-bit?
The commonly reported build is 32-bit. The application architecture and AutoCAD/ObjectARX generation must match; a 64-bit replacement is not interchangeable.
Will reinstalling Visual C++ fix it?
There is no evidence that acdb15.dll is supplied by a Microsoft Visual C++ Redistributable. Repair the Autodesk installation first. Reinstall a runtime only when a separate error specifically identifies that runtime as missing.
Should I run regsvr32 acdb15.dll?
Normally, no. acdb15.dll is not typically a self-registering COM component. The command does not restore a missing file or correct an AutoCAD version mismatch.
What if the message names AxDb15.dll?
Treat it as a different ObjectDBX ActiveX or automation issue. Do not rename acdb15.dll or substitute one file for the other.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Will SFC recreate acdb15.dll?
Normally, no. SFC and DISM repair protected Windows components. They are appropriate only when there is evidence of broader Windows corruption.
What is the safest fix?
Repair or reinstall the exact Autodesk product that needs acdb15.dll, then verify that any plug-in uses the matching AutoCAD generation.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
