Hovering the mouse over the Taskbar Icon gives a nice preview of each tabs content.
This is all good but what if you just want something simpler?
when you obtain done that, you will see a condensed listing for all of Operas preferences.
There is one Preference Category that we need to look for…User Prefs.
After scrolling down and finding the User Prefs category you will need to expand the section.
Scroll down until you find the Use Windows 7 Taskbar Thumbnails entry.
Scroll down once more until you reach the end of the User Prefs category and click Save.