I believe that HP 2000 has a broadcom wireless adapter. Check in BIOS or online, if so there is a glitch that maybe giving you issues. I have successfully install 12.04 on HP 2000 without issue but here is what you may have to do.
First - plug into WIRED internet (you will need this in a moment).
Second, check if 12.04 has blacklisted Broadcom Adapter
cat /etc/modprobe.d/* | egrep 'bcm'
if it finds: blacklist bcm43xx – then you need to REM this line in blacklist.conf file
sudo gedit blacklist.conf
put # before line blacklist bcm43xx, then SAVE and CLOSE blacklist.conf
Third - install the better Broadcom Wireless Adapter drivers
sudo apt-get install b43-fwcutter firmware-b43-installer
After it intalls disconnect your wired connection and restart your computer. You will now see both WIRED and WIRELESS networks under networking icon in top tray.