Thank you for reaching out and letting us know about challenges you're facing, Madeleine. I understand your frustration and how stressful this situation must be, especially with payroll deadlines fast approaching, Madeleine34608.

Issues like this happens due to a corrupted hard drive, damaged program files, issues with your QuickBooks Desktop installation or even a problem with your Windows operating system. Since you've already tried the troubleshooting steps provided by my colleague @JaneDave_I without success, let's proceed to additional steps that will fix the issue. 

One effective solution is to run the QuickBooks Install Diagnostic tool from the QuickBooks Tool Hub. This tool helps automatically detect and repair errors related to Microsoft components the QuickBooks relies on.

Here's how:
 

1. Open the QuickBooks Tool Hub if it's not already open.
2. In the Tool Hub, select Program Problems.
3. Select QuickBooks Program Diagnostic Tool. Let the tool run. It can take up to 20 minutes.
4. When the tool finishes, restart your computer and relaunch QuickBooks.

If the problem continues, rename the QBWUSER.ini file. This will erase the list of your previously opened company files. Therefore, you need to re-open your company file manually.

To rename the file:

1. Open the folder where the QBWUSER.ini file is saved:  Users[Your user name]AppDataLocalIntuitQuickBooks [year]
   If you can't see the folder, you might need to enable hidden files and folders.
2. Right-click the QBWUSER.ini file and select Rename.
3. Add .old at the end of the file name (as in QBWUSER.ini.old).
4. Rename the EntitlementDataStore.ecml file.
5. Reopen QuickBooks Desktop.

If the program opens after renaming either QBWUSER.ini or EntitlementDataStore.ecml, attempt to open a sample company file.
 

If the sample company file opens but your own file does not, try copying your company file to a different location (preferably a local folder rather than a network location) and open it from there. If this works, the issue may be related to a damaged folder or incorrect folder permissions.
 

If you still can’t access your company file, your company file may be damaged. In this case, restore an earlier backup of the file and try opening it again.
 

If the sample company file doesn’t open or QuickBooks still won’t start, the QuickBooks installation itself may be damaged and will need to be repaired or reinstalled.

If you need further assistance or guidance while running the tool, feel free to contact us. We'll be more than happy to help you.