How do I use Aero Desktop? Help!

I cannot use Aero on my system. I am not able to turn it on. I found the settings under Control Panel > All Control Panel Items > Performance Information and Tools > Adjust Visual Affect. I had configured on maximum visual effect. But still when I go inside change theme and try to enable Aero it is not working. I had tried to manage the settings manually but does not looks to be working well. Can anyone help me here to find out the problem behind this.

It can be due to the video drivers. You can update the same and then checkout. Your video memory might be not capable of running the aero. You must simply try to update the drivers first. I had gone through similar issue on my laptop. I updated to Vista. The theme was very basic. I found later on that my video memory is not capable of giving out proper visual affects.