Chrome Start page changed to AVG 2013 search page for no reason ?

Summary:

The tools involved: Windows 7, AVG 2013, Chrome 25. 

The problem: AVG search page suddenly became my start page. 

                      No change in settings. 

                      No AVG Toolbar.  

                      No plausible explanation. 

The solution: Killing a wayward  Chrome process surviving in the background. 

                     (Reboot would have worked just as well. ) 

The full story: 

I love AVG and consider it, currently, as an excellent Anti-Virus to have on one's Windows OS.  

(Warning: Anti-Viruses recommendations, very much like fashion, are a matter which changes quickly and greatly  over time. The best Anti-Virus of the previous year may not be among the top three a year later. Time, in an age where Computer Viruses and Malware evolve in the speed of the information revolution, is of the essence). 

This was why I became worried when I discovered that my favorite browser,  Google Chrome  (Web browsers recommendations, just like Anti-Viruses, also tend to change quickly over the timeline), insisted on opening AVG's search page, and not the prescribed pages I like getting when opening the Browser. 

It was a funny little problem. 

Everything appeared to be in order. 

• The settings of Google Chrome did not change. 
• I did not find an Extension (Add-on) which could explain this phenomena.
• A search on the web  indicated that a toolbar is the common cause others encountered.

To be on the safe side, I sought for a way to identify the presence of a toolbar and its removal method, just in case it is installed as a software component and not as a Browser Extension. 

Sadly, it  turned out that AVG's own replies  regarding changing installed components, as documented on their web site, were no longer correct (Alas, the vailidy of documentation, just like recommended Anti-Viruses and web browsers, is also time-sensitive). 

Thus one had to resort to Control Panel\Programs\Programs and Features\right click on AVG  and choosing change, which finally brought me to the component selection menu (after AVG's Installer startup there was a Next needed there, for those following meticulously, before the selection menu was reached). 

Alas! The components menu did not offer any component which resembled those claims on the web regarding an AVG toolbar forcing a different startup page. 

And thus I returned  to square one. 

To be on the safe side, I closed (Again) all Chrome instances, and then took a look at the Task Manager. And there it was - a wayward Chrome process, still opened (for reasons that will necessitate future - traces). 

Killing it solved the problem.  

Which brings to one's mind the old maxim of computing-operation: reboot. Had I been desperate enough to reboot, the problem would have been solved, without any realization who is the culprit.

But after all is said and done, the really bothering question, remains unanswered as of yet- how and why did a wayward chrome process change the starting pages of all new opening tabs ?