Windows 7: Windows takes a long time to initialize network stuff ...

Since few weeks, I have the problem that after I start my computer, Windows loads something .. I don't know what it is, but it takes few minutes. In the meantime, applications start delayed, especially Firefox. At the right side of the taskbar where are the icons are, there is a icon which indicates that Windows is something loading .. here is an screenshot of that: http://img6.imagebanana.com/img/un2bqrnp/Untitled.png Any ideas?

You probably have a lot of startup programs/services loading on startup, disable some of those.
Startup Programs - Change (See Method 3)

Run a Malware scan with Malwarebytes
That's just your Network connection status. (Your system is probably trying to identify a Network)

I just scanned my computer for malware. There is all OK. After clicking on the icon, a window appears where are my networks listed. There is just my local home network and another network called "VirtualBox Host-Only Network". I hadn't this issue before I installed VirtualBox, so I think maybe my network initialization is so slow due VirtualBox. Is there a way or hack/tweak/something like that to fix that?

Yes, by disabling the connection for the virtual box.

I found the issue. It was MySQL. In the services.msc there is an entry called MySQL, right click on MySQL ==> Properties ==> Startup type ==> disabled. Now the network initialization is much faster!