MDT 2010: Incorrect wimgapi.dll version causing WIM mounting issues

Today’s blog will cover an issue we have seen with Microsoft Deployment Toolkit 2010.  You may see one or more of the following error messages when generating or updating boot images and other actions in MDT that involve the Lite Touch Images:

• Unable to mount the WIM, so the update process cannot continue.
• Unable to load DLL 'wimgapi.dll'
• Mount did not succeed

You can also run into errors when Windows System Image Manager tries to catalog an image.  This issue can occur because we are finding an incorrect version of WIMGAPI.DLL first in the path

Steps to Resolve

At a command run the following command

Where wimgapi.dll

For the first location listed in the page verify that the .DLL Version is correct.  If MDT 2010 is installed on Windows 7 or Windows Server 2008 R2 you should see wimgapi.dll in two locations because it ships with the operating system and with the Windows Automated Installation Kit (WAIK). 

C:\windows\system32\wimgapi.dll
C:\program files\windows imaging\wimgapi.dll

Both versions should be 6.1.7600.16385.  The version could be later than this if any updates have shipped that replace this file at a later date

Notes: 

• This issue can occur if you installed a beta version of the WAIK or System Center Configuration Manager (SCCM)
• You may find other versions in locations like Program Files(X86) or other directories.
• If MDT is installed on Windows XP or Windows Server 2003 wimgapi.dll should only be found in C:\Program Files\Windows Imaging
• The version of WIMGAPI.DLL may be updated in later releases of the Windows AIK or updates to Windows. 

Scott McArthur
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support