According to Intuit, error code 80029c4a is accompanied by the error message:
Error Code 80029c4a: Description Error Loading Type Library.dll
It’s caused by a damaged or incorrect version of Microsoft’s typelib.dll, normally found in the following location:
To fix this error, update QuickBooks to the latest release. To verify your version and release of QuickBooks, press F2 while QuickBooks is running to display the Product Information window. The Product field shows the version and release at the top left of the window. In the example below, Premier Accountant Edition 2009 is the version and R3P is the release. To update QuickBooks, click the Help->Update QuickBooks… menu selection.
After updating QuickBooks, run reboot.bat. Reboot.bat is a batch file supplied with QuickBooks. For the 2009 version, it is normally found in the following location:
C:Program FilesIntuitQuickBooks 2009
Once reboot.bat has completed, restart your computer and launch QuickBooks. If the error persists, you’ll need to perform a clean install of QuickBooks. Once you perform a clean install of QuickBooks, be sure to update QuickBooks to the latest release.
For more information on this error, consult this Intuit knowledge base article.