Tiling an array of projectors has become a practical way to construct a high resolution display system.Unfortunately, such high-resolution display systems have limited use because they require specially developed parallel visualization programs that run on a custom-designed parallel machine or a PC cluster. This paper presents an automatic alignment mechanism for arbitrarily tiled displays running a desktop environment so that users can run ordinary applications developed for desktop PCs. The system consists of three primary procedures: detecting projector misalignment, calculating corrective transformations, and real-time warping for the desktop environment. This allows users to run any 2D, 3D or video applications without modifications or special hardware support. Our experiments indicate that the system is able to achieve sub-pixel accuracy and achieve real-time warping with minimum system performance degradation.