Few user of Microsoft Excel having issue with mouse Scroll, in place of moving up and down its acting as Zoom in/ Zoom out.
Here the solution to reverse it back to normal
Click the Office button (the circle button in the upper left of the Excel screen) and at the bottom of that menu, click “Excel Options”.
In the Options dialog,, click on the “Advanced” item on the left of the screen.
In the middle of the list of “Editing Options”, there is an check box with the caption “Zoom on roll with Intellimouse”. Uncheck that item.