Did you by chance read the comments section after the article? Some readers have found workarounds with varying success.
You do have Aero enabled as your Theme, right?

Go to Control panel.Open personalization.Is your theme Vista?If not reset it to Vista.All changes are done in this location.
That being said,to run aero you require sufficient ram.If not your computer will reset as Vista basic.You require home premium to get all the bells and whistles. however,I still had to upgrade my ram to enable aero to run smoothly.
Sometimes when working and you have a number of windows open,you can lose your aero features.Close some windows and reset.Check your color scheme and enable Vista aero.
All can be done under control panel personalization.Hope this helps.

Responding to: Rhillo

My computer, HP Pavillion m8120n with Vista Home Premium, has all the required specs to run Windows Aero. I've had this computer for almost a year. Like I said in my first post, Windows Aero was working fine until last Sunday.

I'm pretty sure I have all the updated drivers (as I install updates from time-to-time when being prompt). I've looked around on the internet for a solution, but none seems to work for me.

Hi Lighthouse;yes.been awhile (R)