The wireless assistant is software. Vista should be able to use its own system programs to enact and operate your wireless LAN, anyway, but let's see if it's running.
Go to your Start Menu. In the white-space type "msconfig."
Click the "Startup" tab.
This is a list of all the software that's scheduled to boot at Vista startup, and you can arrange it by name, manufacturer, by Command Line command, and by file location.
Left-click once on Manufacturer. Now the startup programs are arranged from Adobe to Unknown. The Hewlett-Packard application you're looking for is "HP Wireless Assistant."
Verify its check-box is checked.
Now go to the "Services" tab. Left-click on Manufacturer again and scroll down to Hewlett-Packard services. All of them should be running. Select any that are unselected and click "Apply." If prompted, run without restart.
If you had to change anything, restart the computer and see if your LAN is still giving you trouble, if it is, carry on with the following in "msconfig."
Now go to the "Tools" tab and "Launch" "System Information."
Expand the "Components" list and see if there is anything listed in "Problem Devices." If there is, reply to this post.
Next, expand "Hardware" and open "I/O." If anything comes up as not "OK," reply to this post with the full name of the hardware. Do the same with the next list down, the "IRQ" list.
I
think you have a Broadcom wireless receiver/transceiver, so your hardware list should list a Broadcom adaptor.
You need to find out what type of device you have, and you need the specific model number of your computer to do that.
(For instance, here's my specifications for my Hewlett-Packard dv6936us rig:
Product Specifications HP Pavilion dv6936us Entertainment Notebook PC - HP technical support (United Kingdom - English))
Find yours
from this list of all the dv6000 models here and see what's under "Wireless Connectivity" and reply back with that hardware's manufacturer and model number stuff.