Solutions to Troubleshoot QuickBooks Error Code 80029c4a
Here are some of the solutions given to fix the temporary error. After fixing the error, you can proceed with handling financial tasks:

Solution 1: Scan the PC

You need to scan the computer system in order to get rid of the error code.

Solution 2: Open the Reboot.bat File

First, you have to open the QuickBooks Desktop.
You need to access the folder in which the reboot.bat file is previously saved.
You need to right- click on the QuickBooks icon.
Click the properties icon.
Hit on open file location.
Right-click on the reboot.bat file.
Click on run as system administrator.
Now, you have to use the reboot.bat as administrator.
Note- make sure that you don’t close the window.
Finally, restart the system again.
Solution 3: Run the Windows System File Checker

First, you need to click on the start option.
Type command in the given search box.
You have to type ctrl + shift keys together.
Hit yes. With this, a black box will be displayed on your system.
Press SFC/scannow.
Now, follow the online instructions.  
Solution 4: Uninstall and then Reinstall the QuickBooks Desktop

Firstly, you need to click on the file menu and then log off option.
You are required to run the file menu and then hit exit.
Click on run as administrator option.
You have to click the help menu and then press on update QuickBooks.
Click the options tab and then select mark all.
You need to click on save.
You have to click update now.
Close the QuickBooks desktop.
Finally, click on yes.
Solution 5: Reinstall the QB Software

Steps for Windows Vista and 7

Initially, you have to go to the start icon and then hit programs and features.
Click on the control panel.
You are required to click on programs and then choose programs and features.
Now, look for the error 80029c4a associated program.
Click on the QuickBooks Pro linked entry.
You need to hit uninstall.
Follow the online instructions.  
Steps for Windows 8 & 10

First, click the Windows option.
Now, hit programs and features. With this, click on apps and features.
Search for QuickBooks error 80029c4a related program.
You need to click on the QuickBooks Pro linked entry.
You are required to choose uninstall/change.
Lastly, read the prompts.
Steps for Windows XP

First, click the start icon and then choose programs and features.
After that, you need to click on the control panel.
You have to click on add or remove programs.
Look for the error 80029c4a.
Hit QuickBooks Pro associated entry.
You need to click on the uninstall icon.
You have to read the prompts.
Solution 6: QuickBooks Window Repair

First of all, shut down QuickBooks.
Click the windows option.
You have to hit on control panel.
You need to uninstall QuickBooks.
Click QuickBooks by going to the programs list.
You are supposed to click on uninstall.
Click next.
You need to close the repair option.
You are required to click on the finish.
Finally, the last step is to reboot the system