From the name of the file I would guess that apitrap.dll has something to do with stopping virii from attaching themselves to certain files, trapping them if you will. API are calls that programs make to the operating systems. For example, if you want to pring something to a printer, then the program must make a call to the operating system. Then the O/S checks to see if the printer is not being used. If it is not in use then it sends the "OK" to the program to print. If it is busy, then it informs the program that the printer is busy and to try again later.<br><br>>But I don't see much about the "why" of things, as opposed >to the "how". Thanks for your help.<br><br>As far as this statement goes, from the information that I have seen you are right. How I learned, was by experimenting, reading and asking around. If you want to understand how computers work, maybe you should enroll in a computer repair course. They do help fill in the gaps, although it is not for every one, it is a good learning experience. An introductory course usually delves into the electronic guts and gives you a feel for the electro-mechanical workings of the various parts of the computer. If you want to learn how the software works, not just use the software, why not take an intro programming course. Visual basic is good for beginners.<br><br> <p> fenris<br><a href=mailto:fenris@hotmail.com>fenris@hotmail.com</a><br><a href= > </a><br> I am interested in Mining Software, as well as Genetic Algorithms.