Data loss due to STOP error message post unsuccessful registration of DLL files

The Olemsg32.dll and Cdo.dll files (all versions) are primarily used to implement messaging and collaboration functionality into a custom application. Once you install these files into your system, you need to manually register these files by using Regsvr32 (regsvr32.exe full path and file name as Olemsg32.dll or Cdo.dll files). A STOP error message might occur if you register these files from a wrong installation point. In such situations, the data stored in the hard drive becomes inaccessible. In such data loss scenarios, you need to restore data from an up-to-date and valid backup to regain your lost data. However, if no such backup is available or backup fails to restore the required data, then you need to opt for advanced data recovery software.

As a practical scenario, you encounter the below error message when you use Regsvr32.exe to register the Olemsg32.dll or Cdo.dll files:

“LoadLibrary ("olemsg32.dll") failed.
GetLastError returns 0x0000007e. LoadLibrary ("cdo.dll") failed.
GetLastError returns 0x0000007e.”

Once the above error message appears, the system becomes unmountable making the data saved in the hard drive inaccessible.

Cause:

The root cause for the occurrence of the above error message is the calling of Olemsg32.dll and Cdo.dll files from the wrong installation point.

Resolution:

To resolve the issue and access the data, you need to follow the below steps:
1. Copy the Olemsg32.dll or Cdo.dll file to the below location:
C:\Program Files\Common Files\System\Mapi\1033\NT folder
2. Next, register the files by using Regsvr32.exe. For example, type the below command:
Regsvr32 Olemsg32.dll
The following message is displayed to indicate that the command is successful:
DllRegisterServer in Olemsg32.dll succeeded.

However, if the problem persists even after following the above steps, the best option left is to reinstall Windows. A clean reinstall of Windows will erase all data from the selected hard drive partition. To recover the lost data from a formatted hard drive partition or volume, you need use powerful data recovery software. These data recovery applications use advanced scanning mechanisms to recover lost data. Built with highly graphical user-interface, automated recovery procedure and advanced features, these data recovery tools serve as precise and recovery centric tools.


Stellar Phoenix Windows Data Recovery is an efficient data recovery utility. It provides complete recovery of lost data from corrupted, deleted, formatted or lost hard drive partitions and volumes. The software supports 185 different file types that can be further extended. The tool is compatible with FAT16, FAT32, VFAT, NTFS and NTFS5 file systems. It supports Windows 7 (Currently in RC1), Vista, XP, 2003 and 2000.