Can't enable HP Wireless Assistant

Greetings,

I have some serious problems with the wireless function on my HP Pavillion DV6000 laptop. I have recently bought this laptop with a preinstalled Windows Vista on it. The Wireless Assistant worked flawlessly under Vista. Nevertheless I found that Vista worked too slow on my HP Pavillion, so I deleted it and installed a Windows XP Professional with Service Pack 2. I also downloaded all WinXP drivers directly from

Now everything work smoothly except the wireless connection which I can not make work at all. No matter in which position - on or off - I turn the Wireless switch, the indicator light remains red and I get the same message every time in the pop up window at the bottom of the display:

"HP Wireless Assistant WLAN: Disabled"

I have tried to fiddle with various settings in Windows without avail. Anyone has any idea what can be wrong, and what shall I to do for getting it work?

Thanks in advance for any advices, Gyorgy