Help, please. I have a pavilion dv4000 and I'm pulling my hair out. Having a serious issue with the touchpad. Have tried everything and even contacted hp support but because of no mouse functions, I can't read my e-mail. So if anyone can help me, PLEASE reply here so I can retrieve the info. Thanks for taking the time.

First, I think you need to get yourself a usb mouse. You can navigate without the mouse it just harder. Tabs, arrows, and your windows key. What happened to the laptop was it damage? If its damage you going to have to set it to get fixed.

If its not the damage hardware it is most probably the drivers for the touchpad? Did you perform a update or install new hardware? If you made some type of hardware change recently you can try a system restore. This could correct driver conflict. Then if that doesn't work download the new drivers for the touchpad it can be found on the HP site.
Download it to your desktop.

Then remove the touchpad hardware from the hardware device manager. And then restart it should recognize new hardware windows may have the drivers and it just may work without the hp driver. If it asks you to locate the drivers... select the hp drivers you downloaded from the site.

To get to the device manager, without the mouse.
Hit the windows key.. arrow to the control panel enter,
Hit tab until the one of the icons in the control panel window is selected, arrow until you get to the system icon.
On the top there are tabs general, system restore.. etc arrow until you have the hardware in view.
Then tab until you get to device manager. To scroll it is down arrow to expand is left arrow. Find the touchpad hardware.. then it "alt" "right arrow" to "action" and "uninstall".

Hope this helps