Problem with Wirless Networks

Hi,

I am having a problem with the finding wireless networks,
The problem started that sometimes I was not able to view wireless networks
even though the wireless is turned on and sometimes I am not able to see
certain networks, however I was able to view the networks sometimes on
restarting or at a later time.

The problem is that now while I am connected to a wireless network,
sometimes it just disconnects and "Connect to a network " views that it
can't find any wireless networks (even though my colleague next to me can see
them and is still connected) and if i try to troubleshoot it tells me that my
wireless device is switched off even though it is still on and if i actually
switch it off it is not recognized to be switched off (the color indicator
for off and on doesn't change )
The only way that I can connect again is to restart (and sometimes I have to
do it more than once before I can see wireless networks again)

I am not sure if it is a Vista problem or a hardware problem ...

I have a HP Pavilion dv6000

Hope someone can help me

Thanks for your time ,