論文アブストラクト：Users must manage frequent software and operating system upgrades across multiple computing devices. While current research focuses primarily on the security aspect, we investigate the user's perspective of upgrading software. Our first study (n=65) found that users delay major upgrades by an average of 80 days. We then ran a field study (n=14), beginning with in-depth observations during an operating system upgrade, followed by a four-week diary study. Very few participants prepared for upgrades (e.g., backing up files), and over half had negative reactions to the upgrade process and other changes (e.g., bugs, lost settings, unwanted features). During the upgrade process, waiting times were too long, feedback was confusing or misleading, and few had clear mental models of what was happening. Users almost never mentioned security as a concern or reason for upgrading. By contrast, interviews (n=3) with technical staff responsible for one organization's upgrades focused only on security and licensing, not user interface changes. We conclude with recommendations to improve the user's upgrade experience.