Windows 7: Can't get the taskbar transparency

I had bought HP Pavilion dv7 series 2 years ago and it came with windows 7 in it. The tranparency worked. Today I replaced the hard drive and installed new windows from a CD, and apparently the video card doesn't support that anymore? Is video card within a HDD, so I also replaced the video card, or is windows going berserk? How do I get the transparency back?

I would say all you did replaced was the hard drive the video card is integrated to your motherboard most likely.
I would recommend you go to this site and download the video card drivers and install them HP Support & Drivers | United States
Jerry

I allready updated the drivers, problem remained the same.

A replacement of a hard drive should not effect the transparency. Check whether your aero is turned on - in Control Panel\Appearance and Personalization\Personalization\Window Color and Appearance

Hi,
I can't get to that window. When I click on window color, I get a new window (see picutre below)

And when I click the troubleshot message, after noticing that aero theme can't be loaded, I click next, when this message appears: "The current video card may support Aero with a driver that is compliant with the Windows Display Driver Model (WDDM). Contact the manufacturer of your computer or video card for a WDDM-compatible driver."
I click next and get to the following window:

I also went to the device manager and tried to manually update the drivers, but is says the drivers are allready most recent.

Type 'aero' into Start/Search and go to where the arrows point.

Can't get there either....

Edit: Is ti possible that some windows don't support aero theme? Because the widnows I got with the computer were allready installed on it, and the windows I have now are from a CD i got at home.

That is strange. Can you go here:

Nope, there is no such thing on my windows...

GOT IT!
The graphics card drviers were, for some reason, not installed.... After I installed them it works.