Cardfile is a personal information manager that was distributed with Microsoft Windows starting from the original version 1.01 until Windows NT 4.0 Server. Cardfile is also included with Windows 98 and Windows Millennium Edition, but has to be installed manually from the installation CD-ROM. Beginning with Windows 3.1, Cardfile supported Object Linking and Embedding. The version supplied with Windows NT versions was a 32-bit application with unicode support. Both later versions could read .crd files created by previous versions.