With the ever increasing amount of digital information, users desire more screen real estate to process their daily computing work, and might well benefit from using a wallsize large high-resolution display instead of a desktop one. Unfortunately, we know very little about users' behaviors when using such a display for daily computing. We present a week-long study that investigates large display use in a personal desktop computing context by comparing it with single and dual desktop monitor use. Results show users' unanimous preference for using a large display: it facilitates multi-window and rich information tasks, enhances users' awareness of peripheral applications, and offers a more "immersive" experience. Further, the data reveals distinct usage patterns in partitioning screen real estate and managing windows on a large display. Detailed analysis of these results provides insights into designing interaction techniques and window management systems more s...