Please start from re-installing the application.

If this does not help, proceed further.

In Windows, MS SQL integrates with OS deeply, and it may be difficult to change the situation if something went wrong.

So we have to resort to radical measures. Some customers report that they could restore the proper MS SQL operability only after re-installing the OS completely.

Before reinstalling the OS, however, please try this:

Please try to change the sector size of your hard drive, using the process described here:
https://learn.microsoft.com/en-us/troubleshoot/sql/database-engine/database-file-operations/troubleshoot-os-4kb-disk-sector-size?tabs=registry-editor#resolution-steps-for-disk-sector-size-errors-in-sql-server :

1. Run Registry Editor as an administrator.
2. Navigate to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\stornvme\Parameters\Device.
3. Select Edit > New > Multi-String value and name it as ForcedPhysicalSectorSizeInBytes.
4. Right-click the name, select Modify, and type * 4095 in the Value data field.
5. Select OK and close Registry Editor.
6. Re-start your computer.

Then please try reinstalling TO3000.

If this does not help:

Note: the below actions are likely to interrupt all SQL-related apps on your computer.

For example, MemoQ uses MS SQL as well. These may also affect older versions of TO3000 operation.
So make all necessary backups and proceed with caution.

0. Uninstall all versions of TO3000 (3D and later)

1. Open Settings
- Press Win + I or click Start → Settings

2. Go to Apps
- Click Apps in the left sidebar
- Select Installed apps

3. Search for SQL apps
- In the search bar at the top, type: SQL
- This will filter and show only apps with "SQL" in the name

4. Uninstall each app
- Click the three dots (⋯) next to each app
- Select Uninstall
- Follow the on-screen prompts

5. Repeat for all SQL-related apps in the list

Then physically delete MS SQL folders from your computer.

The default locations to purge are:
"C:\Program Files (x86)\Microsoft SQL Server\120"
"C:\Program Files (x86)\Microsoft SQL Server\160"
"C:\Program Files\Microsoft SQL Server\120"
"C:\Program Files\Microsoft SQL Server\160"
"C:\Users\Public\Documents\AIT\TO3000, Version 5D"
"C:\Users\Public\Documents\AIT\TO3000, Version 3D"
"C:\Users\Public\Documents\AIT\TO3000, Version 3D+"

After that, please restart your computer and install TO3000 again - with the Empty database option - and restore your database from backup in TO3000.