It is aggravating when programs don't offer the option of "associate with files" during installation. Keep in mind that some do offer this, but only if you select the "custom installation", rather than "typical" installs. I can live with one or two file association changes, but when a program handles multiple files and changes all of them without asking, and you spend lots of time changing them back, I feel it should be only fair to send them a bill to compensate you for your time. Keep in mind too, that if a program didn't associate itself, it would open up a whole new can of worms for those that are less computer literate. Would Autocad override Vectric or another software if you installed it second? I think that most programs just try to make it as easy and painless as possible using the settings that the average user would want.