Summary: After upgrading Outlook from 2003 to 2007, some users may get a DLL error showing a file is missing from the installation. The article will show you some manual techniques to overcome the problem and professional software to help you in repairing data file.

My colleague was using older Outlook 2003, and he wanted to move to its next version Outlook 2007. He upgraded the application and then opened the account, but the account shows the error that ‘this application failed to start because MAPI32 DLL was not found. Reinstalling the application may fix this problem.’
After getting the message, he ran the Outlook PST repair tool (ScanPST.exe), but the error remained the same. At that point, he did not know what this DLL file was and why this error was showing in his Outlook.

What is the MAPI32 DLL file?

The DLL file is the Dynamic Link Library file present in the installation of an application. When a user updated the Outlook version, then new Outlook files are installed in the system. You can also overwrite the DLL file if you install any other email application other than Outlook.

The DLL error occurred when the user tried to upgrade from Outlook 2003 to 2007 directly. During the process of installation and upgrade, the MAPI32.DLL was not updated or replaced properly. It created an incompatibility issue, and the error stopped the account from opening.

Apart from incompatibility issues, there are several causes that can show the same error while accessing Outlook. We are presenting you a list of all probable causes-

  • The MAPI32.DLL is not found at its default location.
  • Outlook cannot file the path of the DLL folder.
  • The DLL file is deleted from its location.
  • A component of the DLL file is missing.
  • The DLL file is corrupt or incompatible with the Outlook version.

In extreme cases, the DLL error can occur due to registry problems, malware or spyware corruption, and even a system hardware failure.Infographics of MSMAPI32DLL error in Outlook

How to fix the MAPI32.DLL file error?

  • Recreate the DLL fileYou can rename the file, and then Outlook will recreate it again. Follow the process-
    1. Open Windows Explorer and open the C drive.
    2. In the Program Files, go to Common Files, then open the System folder.
    3. Open the MSMAPI folder, then open the 1033 folder.
    4. Choose the MSMAPI32.DLL file and right-click it. Choose the Rename
    5. Rename the MSMAPI32.DLL to MSMAPI32.OLD and save it.
    6. Now start Outlook. Outlook will try to find all the required program files like the DLL, and when it does not find a relevant one, it will recreate it with a compatible DLL.
  • Run the anti-virus scanIf you suspect that a virus is affecting your system and Outlook is getting affected by it, then you can run a thorough scan of the system using anti-virus software. The anti-virus will look for all the affected files and remove viruses.
  • Reinstall Outlook
    DLL files are important for any application to run properly. When the upgrade from Outlook 2003 to 2007 is not properly completed, there will be several shortcomings in the installation and program files. You should reinstall Outlook and add an account.
  • Run the disk scan
    The “sfc /scannow” cmdlet can scan the whole disk and restore the incomplete files like MAPI32 DLL. It can also show various problems in the hard disk sector.
  • Repair your PST file
    If the error on MSMAPI32 DLL occurs after adding your account in Outlook, perhaps the PST file has become affected due to improper setting or bad installation. You should repair the PST file using either a ScanPST tool or a professional PST repair software to recover your mailbox items. For repairing PST files, you can use Outlook PST Recovery, an outstanding tool recommended by experts. It repairs a damaged PST file and saves it to a new PST file. It is known to fix almost all known issues irrespective of the size of the PST file. Also, this tool supports PST files of all Outlook versions, including Outlook 2019.

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Upgrading your Outlook application is beneficial, but errors like MSMAPI32 DLL can wash out the whole upgrade process and delete the existing mailbox content. To recover the items present in the PST file, you should use Outlook PST Recovery software.

The software will access the PST file and recover all the mailboxes present in it. It can even recover the deleted items. The software cannot help you install Outlook correctly, but if something is gone wrong, it will recover the entire mailbox with complete folders. Later, you can save the data in a new PST file directly.