1554: Shared Folders Cannot be Accessed after Installation of an Acronis Product

Last update: 16-11-2010

Try solving the issue by increasing the IRPStackSize value


Shared folders that reside on the machine cannot be accessed after installation of an Acronis product on the machine.

Virtual (mapped) drives disappear in Windows Explorer after installation of an Acronis product. The network, however, is still accessible from Windows.

You may also receive error messages similar to the following ones when trying to connect to a shared folder:

  • Not enough server storage is available to process this command;
  • \\Computer\share is not accessible. Access denied;
  • This connection has not been restored;
  • Not enough memory to complete transaction. Close some applications and retry.


The problem is that Microsoft Lanman Server has a fixed limit on the quantity of filters it supports. Since Acronis product installs some filters to work, the total number of filters can exceed the server's limit. The same problem may occur after installation of an Antivirus product and is described in the Microsoft Knowledge Base Article 177078.


Please refer to the Microsoft Knowledge Base Article 177078 for a workaround (also applies to Windows Vista, Windows 7 and Windows Server 2008).

If you create the IRPStackSize value as described in Step 4 in the Microsoft article, the default value will be 15. It is recommended that you increase the value by 3.
Then reboot and see if it works. If it does not, increase the value by 3 again (to 21, for example) and reboot again. If you get to 50 and it still does not work, the issue is most likely not caused by the IRPStackSize value.

More information

Please contact Acronis Support if the described workaround does not help.