You're here because you have a file that has a file extension ending in .ndb. Files with the file extension .ndb can only be launched by certain applications. It's possible that .ndb files are data files rather than documents or media, which means they're not meant to be viewed at all.

The NDB file extension is known as the Act! Notes Database file which was developed by The SageGroup. The Act! for Notes is a customer relationship management (CRM) software application used to monitor client and prospect details in a single database that can be shared by multiple users. The NDB file extension is used in the Notes section of this application, which is made for an easier management of the user's daily responsibilities. Specifically this format was used in the second version of the program for Windows application. Users can attach text notes to the program and save them with the NDB file extension for future reference. When a file is attached to a contact (on the Notes/History tab), the file is not saved in the database. ACT! saves the attachment as a shortcut to the location where the existing file resides. To be sure the attachments are viewable by all ACT! users on the network, it is suggested to save the files needed to be attach to contacts into the Document folder being shared on the server, or in another folder in the ACTSHARE folder on the server.

Launch a .ndb file, or any other file on your PC, by double-clicking it. If your file associations are set up correctly, the application that's meant to open your .ndb file will open it. It's possible you may need to download or purchase the correct application. It's also possible that you have the correct application on your PC, but .ndb files aren't yet associated with it. In this case, when you try to open a .ndb file, you can tell Windows which application is the correct one for that file. From then on, opening a  .ndb file will open the correct application. Click here to fix .ndb file association errors

Be careful not to rename the extension on .ndb files, or any other files. This will not change the file type. Only special conversion software can change a file from one file type to another.

A file extension is the set of three or four characters at the end of a filename; in this case, .ndb. File extensions tell you what type of file it is, and tell Windows what programs can open it. Windows often associates a default program to each file extension, so that when you double-click the file, the program launches automatically. When that program is no longer on your PC, you can sometimes get an error when you try to open the associated file.