Rightclick on the wireless icon in SysTray to Troubleshoot.
Do you have HP Wireless Manager also running in System Tray. You need to set it to Allow Independent Wireless manager before disabling it, or it will often block the signal or disallow use of just the device without the HP bloatware. Turn off any other wireless software in msconfig>Startup.
Troubleshooting Steps for Windows 7
This brings up whether this is still an HP bloatware preinstall? HP has the worst load of bloatware and useless factory utilties with better version built into Windows 7. Most tech enthusiasts will not run such a corrupted install but instead
Clean Reinstall - Factory OEM Windows 7.
The latest HP's have a Minimal Factory Recovery that is very close to a Clean Reinstall however keeps the HP Wireless manager. Again, you need to disable it in the Preferences.
You can also
Clean Up Factory Bloatware