Resource Link- www.wizxpert.com/quickbooks-desktop-doesnt-start/
If it was not open after clicking on QuickBooks Desktop, then it could be due to many reasons like Corrupted Hard disk, Improper installation. QuickBooks Desktop Won’t Open is not a big problem. To fix this, understand some of the solutions given below carefully.
Close QBW32.exe process
Renaming the QBWUSER.ini. file
Suppress QuickBooks Desktop Installation
Repair QuickBooks Desktop Installation if done incorrectly
Create a new Windows Admin User
Restart the Desktop
Do a clean installation of QuickBooks

Solution 1: Shut down the QBW32.exe process.
Solution 2: Rename the QBWUSER.ini. ...
Solution 3: Repress QuickBooks Desktop Installation.
Solution 4: Repair QuickBooks Desktop.
Solution 5: Create a new Windows Admin User.
Solution 6: Restart the Desktop.
You may also face QuickBooks error 6129 error when you try to access a company's financial records and the database connection verification fails. An error can occur if QuickBooks cannot connect to the server and cannot access company files. The error message "Error message: Failed to verify database connection. QuickBooks Error 6129 " suddenly appears on the screen. There are various reasons for QuickBooks 61290 to explain in this post and fix it with the most effective solution.