Fix Windows Controlled Folder Access Blocking QuickBooks Desktop Writes
Windows can silently block QuickBooks Desktop company file and backup writes after a security change. Learn the fix that keeps scheduled backups running.
Windows Controlled Folder Access protects local folders from ransomware by permitting only trusted programs to write to them. After a Windows security update changes that behavior, QuickBooks Desktop may be treated as untrusted. The result is often silent: a scheduled backup ends with no new .qbb file, or a company file appears to save but does not persist the latest entries. The repair is to trust the QuickBooks executables, confirm where the company file and backup live, and test the next scheduled backup.
What blocked writes look like
Controlled Folder Access often produces no visible QuickBooks error. The most common sign is a backup folder that still shows an old .qbb file after a scheduled job was supposed to run. Another sign is a company file that will not save, or a QuickBooks message that it cannot save the file. Windows Security usually records the block under Virus & threat protection, then Protection history, under the heading Controlled folder access.
The control to change
Open Windows Security. On Windows 10, use Start, Settings, Update & Security, Windows Security. On Windows 11, use Start, Settings, Privacy & security, Windows Security. Select Virus & threat protection, then Manage ransomware protection. In the Controlled folder access section, choose Allow an app through Controlled folder access.
If Controlled folder access is off, this is not the cause of the blocked write.
Which QuickBooks executables to allow
In the allowed apps screen, select Add an allowed app. Choose Recently blocked apps if QuickBooks appears there. Otherwise choose Browse all apps and add the QuickBooks Desktop executable for the installed year. The typical path is C:\Program Files\Intuit\QuickBooks 2024\QBW32.exe, or C:\Program Files (x86)\Intuit\QuickBooks 2024\QBW32.exe on some installations. If your folder year differs, choose the matching folder. The executable is usually named QBW32.exe.
If the file is used in multi-user mode or the Database Server Manager touches it, also add QBDBMgrN.exe from the same QuickBooks version folder. The manager writes network data files beside the company file.
Adding the company file or backup folder to the general Windows Security exclusions list is not the same control. Controlled Folder Access works by process, not by folder, so the allowed app list is what unblocks the write.
Confirm the folders that are protected
While still on the ransomware protection screen, choose Protected folders. The default list includes C:\Users\username\Documents, Desktop, Pictures, Videos, Music, and Favorites. QuickBooks company files are often stored in Documents, and a backup destination under Documents inherits that protection. Leave the folders in the protected list. The allowed app exception is enough.
Test a manual backup
Close and reopen QuickBooks after adding the executable. Choose File, Back Up Company, Create Local Backup. Select Local backup, then Next. Browse to the usual backup folder, confirm the filename, and run the backup. Check the destination for a new .qbb with today's timestamp and a nonzero file size.
Test a scheduled backup
After a manual backup succeeds, test the scheduled job that failed. Choose File, Back Up Company, Schedule Local Backup and confirm that the original schedule is still listed. Run the next scheduled backup immediately if the scheduler offers that option. If it does not, set a temporary schedule a few minutes ahead and wait for it to run. The scheduled job uses the same QBW32.exe process, so a successful manual backup to the same destination is a strong signal, but a real scheduled run confirms the timing path.
Check the result
After the test, open the backup folder and verify that the .qbb file is new. Then open Windows Security, Virus & threat protection, Protection history, and look for any new Controlled folder access block. If one appears, repeat the allowed app step and make sure you chose QBW32.exe from the correct version folder.
If a blocked write damaged the company file
An interrupted save can leave a .qbw file that later fails QuickBooks Verify. Run File, Utilities, Verify Data. If Verify reports damage, the security setting is fixed but the file needs repair. See our QuickBooks Desktop file repair service for help with Verify failures and damaged transactions.