10 64 bit on a Dell laptop that has 6GB RAM and 1GB graphic card. All of a sudden there were some sudden changes in UI which I am unable to understand why. The unity panel was initially glassy and transparent, now it looks all black in its background. Likewise the alt+tab graphics was working well until it got changed suddenly and now shows icons on pure white background. I've not tried to install any themes and I've not tried to tweak anything. Why did this UI changes occur? Could it be that it is unable to detect the graphic card or something?
How can I fix this and how can I get back the original desktop back? Please help..