Throughout their lives, people are faced with various learning situations, for example when they learn how to use new software, services or information systems. However, research in the field of Interactive Learning Environments shows that learners needing assistance do not systematically seek or use help, even when it is available. The aim of the present study is to explore the role of some factors from research in Interactive Learning Environments in another situation: using a new technology not as a means of acquiring knowledge but to realize a specific task. Firstly, we present the three factors included in this study (1) the role of the content of assistance, namely operative vs. function-oriented help; (2) the role of the user's prior knowledge; (3) the role of the trigger of assistance, i.e. help provided after the user's request vs. help provided by the system. In this latter case, it is necessary to detect the user's difficulties. On the basis of research on problem-solving, we list behavioral criteria expressing the user's difficulties. Then, we present two experiments that use "real" technologies developed by a large company and tested by "real" users. The results showed that (1) even when participants had reached an impasse, most of them never sought assistance, (2) operative assistance that was automatically provided by the system was effective for novice users, and (3) function-oriented help that was automatically provided by the system was effective for expert users. Assistance can support deadlock awareness and can also focus on deadlock solving by guiding task. Assistance must be adapted to prior knowledge, progress and goals of learners to improve learning. (Contains 3 tables and 1 figure.)