How to Fix Oci.dll Not Found or Missing Errors

A Troubleshooting Guide for Oci.dll Errors

Screenshot of an Oci.dll error message
Oci.dll Error.

Oci.dll errors are caused by situations that lead to the removal or corruption of the ​oci DLL file, which is an API used with Oracle software that stands for Oracle Call Interface.

In some cases, oci.dll errors could indicate a registry problem, a virus or malware issue, or even a hardware failure.

There are several different ways that oci.dll errors can show up on your computer. Here are some of the more common ways that you might see oci.dll errors:

Oci.dll Not Found
This application failed to start because oci.dll was not found. Re-installing the application may fix this problem.
Cannot find [PATH]\oci.dll
Failed to load OCI DLL
Cannot load OCI DLL: [PATH]
The file oci.dll is missing.
Cannot start [APPLICATION]. A required component is missing: oci.dll. Please install [APPLICATION] again.

Oci.dll error messages might appear while using or installing certain programs, when Windows starts or shuts down, or maybe even during a Windows installation. However, it usually has to do with an Oracle application.

The context of the oci.dll error is an important piece of information that will be helpful while solving the problem.

The oci.dll error message could apply to any program or system that might utilize the file on any of Microsoft's operating systems including Windows 10Windows 8Windows 7Windows VistaWindows XP, and Windows 2000.

How to Fix Oci.dll Errors

Do not download oci.dll from a "DLL download" website. There are many reasons why downloading a DLL file is a bad idea. If you need a copy of oci.dll, it's best to obtain it from its original, legitimate source.


Start Windows in Safe Mode to complete any of the following steps if you're unable to access Windows normally due to the oci.dll error.

  1. Restore oci.dll from the Recycle Bin. The easiest possible cause of a "missing" oci.dll file is that you've mistakenly deleted it.

    If you suspect that you've accidentally deleted oci.dll but you've already emptied the Recycle Bin, you may be able to recover oci.dll with a free file recovery program.

    Recovering a deleted copy of oci.dll with a file recovery program is a smart idea only if you're confident you've deleted the file yourself and that it was working properly before you did that.


  2. Run a virus/malware scan of your entire system. Some oci.dll errors could be related to a virus or other malware infection on your computer that has damaged the DLL file. It's even possible that the oci.dll error you're seeing is related to a hostile program that's masquerading as the file.

  3. Reinstall the program that uses the oci.dll file. If the oci.dll DLL error occurs when you use a particular program, reinstalling the program should replace the file.

    Pay close attention to the program that you're reinstalling. Some "oci.dll was not found" errors are due to programs that are the wrong bit version, like using a 32-bit application to access a 64-bit Oracle database. In that specific case, you'd want to install the 64-bit equivalent of the application so that it can find the correct DLL file to use with the 64-bit database, or use the 32-bit edition of the application to utilize the 32-bit libraries.

    Try your best to complete this step. Reinstalling the program that provides the oci.dll file, if possible, is a likely solution to this DLL error.

  4. Edit a value in the Windows Registry Editor to fix the Oracle client from loading the incorrect DLL file.

    Find the key HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ORACLE and then right click the ORACLE node and choose to make a new key called Z_SSIS.

    Right click that new key and make a new string called ORACLE_HOME. Open that string and set the value to the location of the 32-bit installation of Oracle.

    If you need help doing these things, see How to Add, Change, & Delete Registry Keys & Values for specific instructions.

  5. Install the Microsoft Visual C++ 2010 Redistributable Package to ensure that any dependant DLLs are installed in order for oci.dll to work properly.

    There's both a 32-bit version and a 64-bit version of the redistributable, so you can follow this x86 link or this x64 link to get either.

  6. Use System Restore to undo recent system changes. If you suspect that the oci.dll error was caused by a change made to an important file or configuration, a System Restore could solve the problem.

  7. Update the drivers for hardware devices that might be related to oci.dll. If, for example, you're receiving a "The file oci.dll is missing" error when you play a 3D video game, try updating the drivers for your video card.

    The oci.dll file may or may not be related to video cards - this was just an example. The key here is to pay very close attention to the context of the error and troubleshoot accordingly.

  8. Roll back a driver to a previously installed version if oci.dll errors began after updating a particular hardware device's driver.

  9. Install any available Windows updates. Many service packs and other patches replace or update some of the hundreds of Microsoft distributed DLL files on your computer. The oci.dll file could be included in one of those updates.

  10. Repair your installation of Windows. If the individual oci.dll file troubleshooting advice above is unsuccessful, performing a startup repair or repair installation should restore all Windows DLL files to their working versions.

  11. Use a free registry cleaner to repair oci.dll related issues in the registry. A free registry cleaner program may be able to help by removing invalid oci.dll registry entries that might be causing the DLL error.

    We rarely recommend the use of registry cleaners. We've included the option here as a "last resort" attempt before the destructive step coming up next.

  12. Perform a clean installation of Windows. A clean install of Windows will erase everything from the hard drive and install a fresh copy of Windows. If none of the steps above correct the oci.dll error, this should be your next course of action.

    All the information on your hard drive will be erased during a clean install. Make sure you've made the best attempt possible to fix the oci.dll error using a troubleshooting step prior to this one.

  13. Troubleshoot for a hardware problem if any oci.dll errors persist. After a clean install of Windows, your DLL problem can only be hardware related.