Scrolling through a window that isn't in focus is a basic feature you'll find in other operating systems, but for some reason it's still missing in Windows. Some mice and pointer devices include dedicated buttons or software to handle it, but if you're using a generic mouse with a standard driver, all you need is a tiny application of a few kilobytes called AlwaysMouseWheel.
Background Scrolling: A Feature Windows Still Lacks
I've seen this work naturally in OS X and on several Linux distributions. Scrolling a page or window that sits in the background is perfectly natural in those environments, so I can't understand why Windows, in virtually every version, still refuses to include it. I'd like to think it's a matter of patents, because we all know how companies like to patent “functions”, “interfaces”, and “user experiences” and so on.
I've also heard that some mice and trackpads come with dedicated software that can enable this behavior. However, on this machine I'm using a generic mouse with the standard Windows driver, so there's not much I can tweak there.
The Solution: AlwaysMouseWheel
The answer comes in the form of an external tool called AlwaysMouseWheel. The program offers two options: bring the window to the front when you scroll, or simply scroll without stealing focus from the current window. Despite its tiny size, it supports more than twenty languages (Spanish is included), and as you'd expect, it also has options to disable the feature without quitting the program (in case you run into any incompatibility), and to launch it along with Windows. AlwaysMouseWheel has no installer, so it's a good idea to create a dedicated folder and drop the executable there if you want it to start with the operating system.
Honestly, I don't have much more to add. The program just works, and I haven't come across any conflicts so far, not even when launching a few games. It may seem like a small detail, but the essence of the famous “user experience” that each operating system considers “superior” to what the competition offers is made up of many such small details, and when they're missing, switching between systems becomes more difficult.
That's not to say every interface should be identical, but the fact that there's no official support for scrolling in the background under Windows is at the very least striking. Fortunately, AlwaysMouseWheel filled the gap in seconds, and it's compatible with every version of Windows (32-bit or 64-bit), starting with Windows XP.
