Microsoft Office DLL CDO.DLL

Download and Repair CDO.DLL Issues

Last Updated: 11/25/2024
[Reading Time Required: 3.5 minutes]

CDO.DLL, also known as a Collaboration Data Objects 1.21s for Windows NT file, was created by Microsoft for the development of Microsoft Exchange. DLL files fall under under the Win32 DLL (Dynamic link library) file type category.

The first version of CDO.DLL was released for the Windows XP Operating System on 05/31/2001 inside Office XP. The most recent version [file version 6.5.6980.13] was introduced on 08/19/2003 for Office 2003.

Please see below for more detailed information, DLL file troubleshooting instructions, and free downloads of different versions of CDO.DLL.

File Analysis Provided by Jason Geater (Author)

File Overview

General Information ^✻
File Name:	CDO.DLL
File Extension:	DLL file extension
Description:	Collaboration Data Objects 1.21s for Windows NT
Object File Type:	Dynamic link library
File Operating System:	Windows NT 32-bit
MIME Type:	application/octet-stream
User Popularity Rating:

Developer and Software Information
Software Developer:	Microsoft Corporation
Software Program:	Microsoft Exchange
Legal Copyright:	Copyright (C) 1986-2003 Microsoft Corp. All rights reserved.

File Details
Character Set:	Windows, Latin1
Language Code:	English (U.S.)
File Flags:	(none)
File Flags Mask:	0x003f
Entry Point:	0x4161b
Code Size:	454144

View Other CDO.DLL Information

File Info	Description
File Size:	717 kB
File Modification Date/Time:	2017:05:10 20:58:11+00:00
File Inode Change Date/Time:	2017:11:05 07:01:42+00:00
File Type:	Win32 DLL
MIME Type:	application/octet-stream
Machine Type:	Intel 386 or later, and compatibles
Time Stamp:	2003:07:30 02:13:42+00:00
PE Type:	PE32
Linker Version:	7.0
Code Size:	454144
Initialized Data Size:	273920
Uninitialized Data Size:	0
Entry Point:	0x4161b
OS Version:	4.0
Image Version:	0.0
Subsystem Version:	4.0
Subsystem:	Windows GUI
File Version Number:	6.5.6980.13
Product Version Number:	6.5.6980.13
File Flags Mask:	0x003f
File Flags:	(none)
File OS:	Windows NT 32-bit
Object File Type:	Dynamic link library
File Subtype:	0
Language Code:	English (U.S.)
Character Set:	Windows, Latin1
Company Name:	Microsoft Corporation
File Description:	Collaboration Data Objects 1.21s for Windows NT
File Version:	6.5.6980.13
Internal Name:	CDO
Legal Copyright:	Copyright (C) 1986-2003 Microsoft Corp. All rights reserved.
Original Filename:	CDO.DLL
Product Name:	Microsoft Exchange
Product Version:	6.5
Comments:
Legal Trademarks:	Microsoft(R) and Windows(R) are registered trademarks of Microsoft Corporation.

^✻ Portions of file data provided by Exiftool (Phil Harvey) distributed under the Perl Artistic License.

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What are CDO.DLL Error Messages?

Dynamic Link Library CDO.DLL Errors

CDO.DLL is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like CDO.DLL, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like accicons.exe - to follow. These files were created so that multiple programs (eg. Office) could share the same CDO.DLL file, saving valuable memory allocation, therefore making your computer run more efficiently.

Unfortunately, what makes DLL files so convenient and efficient, also makes them extremely vulnerable to problems. If something happens to a shared DLL file, either it goes missing or gets corrupted in some way, it can generate a "runtime" error message. Runtime is pretty self-explanatory; it means that these errors are triggered when CDO.DLL is attempted to be loaded either when Office is starting up, or in some cases already running. Some of the most common CDO.DLL errors include:

Access Violation at address - CDO.DLL.
CDO.DLL could not be found.
Cannot find C:\Program Files\Common Files\System\MSMAPI\1033\CDO.DLL.
Cannot register CDO.DLL.
Cannot start Office. A required component is missing: CDO.DLL. Please install Office again.
Failed to load CDO.DLL.
The application has failed to start because CDO.DLL was not found.
The file CDO.DLL is missing or corrupt.
This application failed to start because CDO.DLL was not found. Re-installing the application may fix this problem.

Your CDO.DLL file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with Office), or deleted by a malware infection. Furthermore, CDO.DLL file corruption could be caused from a power outage when loading Office, system crash while loading CDO.DLL, bad sectors on your storage media (usually your primary hard drive), or quite commonly, a malware infection. Thus, it's critical to make sure your anti-virus is kept up-to-date and scanning regularly.

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How to Fix CDO.DLL Errors in 3 Steps (Time to complete: ~5-15 minutes)

If you're encountering one of the error messages above, follow these troubleshooting steps to resolve your CDO.DLL issue. These troubleshooting steps are listed in the recommended order of execution.

Step 1: Restore your PC back to the latest restore point, "snapshot", or backup image before error occurred.

To begin System Restore (Windows XP, Vista, 7, 8, and 10):

Hit the Windows Start button
When you see the search box, type "System Restore" and press "ENTER".
In the search results, find and click System Restore.
Please enter the administrator password (if applicable / prompted).
Follow the steps in the System Restore Wizard to choose a relevant restore point.
Restore your computer to that backup image.

If the Step 1 fails to resolve the CDO.DLL error, please proceed to the Step 2 below.

Step 2: If recently installed Office (or related software), uninstall then try reinstalling Office software.

You can uninstall Office software by following these instructions (Windows XP, Vista, 7, 8, and 10):

Hit the Windows Start button
In the search box, type "Uninstall" and press "ENTER".
In the search results, find and click "Add or Remove Programs"
Find the entry for Office 2003 and click "Uninstall"
Follow the prompts for uninstallation.

After the software has been fully uninstalled, restart your PC and reinstall Office software.

If this Step 2 fails as well, please proceed to the Step 3 below.

Office 2003

Microsoft Corporation

Step 3: Perform a Windows Update.

When the first two steps haven't solved your issue, it might be a good idea to run Windows Update. Many CDO.DLL error messages that are encountered can be contributed to an outdated Windows Operating System. To run Windows Update, please follow these easy steps:

Hit the Windows Start button
In the search box, type "Update" and press "ENTER".
In the Windows Update dialog box, click "Check for Updates" (or similar button depending on your Windows version)
If updates are available for download, click "Install Updates".
After the update is completed, restart your PC.

If Windows Update failed to resolve the CDO.DLL error message, please proceed to next step. Please note that this final step is recommended for advanced PC users only.

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If Those Steps Fail: Download and Replace Your CDO.DLL File (Caution: Advanced)

If none of the previous three troubleshooting steps have resolved your issue, you can try a more aggressive approach (Note: Not recommended for amateur PC users) by downloading and replacing your appropriate CDO.DLL file version. We maintain a comprehensive database of 100% malware-free CDO.DLL files for every applicable version of Office. Please follow the steps below to download and properly replace you file:

Locate your Windows operating system version in the list of below "Download CDO.DLL Files".
Click the appropriate "Download Now" button and download your Windows file version.
Copy this file to the appropriate Office folder location:

Windows XP: C:\Program Files\Common Files\System\Mapi\1033\
Windows XP: C:\Program Files\Common Files\System\MSMAPI\1033\
Restart your computer.

If this final step has failed and you're still encountering the error, you're only remaining option is to do a clean installation of Windows XP.

GEEK TIP : We must emphasize that reinstalling Windows will be a very time-consuming and advanced task to resolve CDO.DLL problems. To avoid data loss, you must be sure that you have backed-up all of your important documents, pictures, software installers, and other personal data before beginning the process. If you are not currently backing up your data, you need to do so immediately.

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Download CDO.DLL Files (Malware-Tested 100% Clean)

CAUTION : We strongly advise against downloading and copying CDO.DLL to your appropriate Windows system directory. Microsoft typically does not release Office DLL files for download because they are bundled together inside of a software installer. The installer's task is to ensure that all correct verifications have been made before installing and placing CDO.DLL and all other DLL files for Office. An incorrectly installed DLL file may create system instability and could cause your program or operating system to stop functioning altogether. Proceed with caution.

Office XP

File Name

Software Version

File Version

Architecture

CDO.DLL

5.5.2654.6

32-bit (x32)

Expand for Detailed File Information +

OS Version:	Windows XP
Software:	Microsoft Exchange
Software Version:	5.5.2654.6
File Version:	5.5.2654.6
File Size:	810256
File Date:	05/10/2017
MD5 Checksum:	577abfa927c60e2379e61812cb6db167
SHA1 Checksum:	29f4a14226f39bc0f57be6dad8e8af23acbd5cfc
SHA256 Checksum:	b01c4b7f3d87012f6b59bbeb65aefa685322dc126f4d3a8f532448f6c574e747
CRC32:
File Directory Location:	C:\Program Files\Common Files\System\Mapi\1033\

File Version, System, and Machine Information
File Type:	Win32 DLL
Image Version:	0.0
Initialized Data Size:	269824
Linker Version:	5.0
Machine Type:	Intel 386 or later, and compatibles
PE Type:	PE32
Subsystem:	Windows GUI
Subsystem Version:	4.0
File Modification Date/Time:	05/10/2017

Office 2003

File Name

Software Version

File Version

Architecture

CDO.DLL

6.5.6980.13

32-bit (x32)

Expand for Detailed File Information +

OS Version:	Windows XP
Software:	Microsoft Exchange
Software Version:	6.5.6980.13
File Version:	6.5.6980.13
File Size:	733752
File Date:	05/10/2017
MD5 Checksum:	394ad5d3570c3bd3a27ebaa63b9d5795
SHA1 Checksum:	e529063db4d12fc1ef7fca533301acf6af8b1559
SHA256 Checksum:	01f55e6a41e01539496dad9f7332e14ccf3ca9c24cc06003a6e2be607f78b6f7
CRC32:
File Directory Location:	C:\Program Files\Common Files\System\MSMAPI\1033\

File Version, System, and Machine Information
File Type:	Win32 DLL
Image Version:	0.0
Initialized Data Size:	273920
Linker Version:	7.0
Machine Type:	Intel 386 or later, and compatibles
PE Type:	PE32
Subsystem:	Windows GUI
Subsystem Version:	4.0
File Modification Date/Time:	05/10/2017

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Files Related to CDO.DLL

DLL Files Related to CDO.DLL

File Name	Description	Software Program (Version)	File Size (bytes)	File Location
WPFEXTENSIONS.DLL	Microsoft.Data.Visualization.WpfExtensions	Microsoft Power Map for Excel (16.0.2410.1000)	79064	C:\Users\Tester\AppData\Local\Microsoft\Windows...
Microsoft.AnalysisServ...	Dynamic Link Library	Office 2013	245440	C:\Users\Tester\AppData\Local\Microsoft\Windows...
Microsoft.ReportingSer...	Dynamic Link Library	Office 2016	85696	C:\Users\Tester\AppData\Local\Microsoft\Windows...
MSOTHUNK.DLL	Dynamic Link Library	Office 95	11264	C:\Users\Tester\AppData\Local\Microsoft\Windows...
MSLID.DLL	Microsoft Language Identification DLL	Microsoft® Language Identification (1.0.2305)	536576	C:\Users\Tester\AppData\Local\Microsoft\OneDriv...

Other Files Related to CDO.DLL

File Name	Description	Software Program (Version)	File Size (bytes)	File Location
WLAN_profile_v1.xsd	XML Schema Definition	Windows 7	15591	C:\Windows\L2Schemas\
WLAN_profile_v1.xsd	XML Schema Definition	Windows XP	15263	C:\Windows\L2Schemas\
WLAN_policy_v1.xsd	XML Schema Definition	Windows 10	7627	C:\Windows\L2Schemas\
LAN_profile_v1.xsd	XML Schema Definition	Windows Vista	2241	C:\Windows\L2Schemas\
LAN_policy_v1.xsd	XML Schema Definition	Windows 8	3472	C:\Windows\L2Schemas\

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