adobe-reader
Middle click and drag in Adobe Reader scrolls the page, as it does in most Windows applications. However, middle click and release (without dragging) shows a page thumbnail.
Is there any way to turn off the thumbnail-showing behavior? It's annoying when I just try to scroll the page and suddenly a box pops up, obstructing the text.
This feature is designed for reading an article in a newspaper or magazine PDF:
In PDFs, articles are optional electronic threads that the PDF author may define within that PDF. Articles lead readers through the PDF content, jumping over pages or areas of the page that are not included in the article, in the same way that you might skim through a traditional newspaper or magazine, following one specific story and ignoring the rest. When you read an article, the page view may zoom in or out so that the current part of the article fills the screen.
To disable the Hand tool from following an article path, go to the the Edit menu and choose Preferences. In the General category, uncheck "Make Hand tool read articles".
For Adobe Reader X, XI:
To make continuous scrolling the default behavior:
Edit » Preferences » Accessibility » Always use Page Layout Style. Check Single Page Continuous.
To only do this for the current session:
Go to View » Page Display and check the option Enable Scrolling (this is only a one-time fix and will be reset the next time you open Adobe).
For Adobe Reader 9:
Go to View » Page Display and check the option Single Page Continuous.
Best Answer
AFAIK there is not a direct way to do this so you have to use some trick like AutoHotkey. There is another question I found where user is using mouse wheel as hand in Adobe reader.
The best way to set the keys according to your wish and do whatever you want to. But I think this will cause to not scroll down through the mouse wheel after this.