Ok, IMO, I would actually back everything up onto an external drive and do a clean install of Windows 7 and then only download the drivers that are neccessary. If you are not comfortable with doing that though, take a look at all the graphics drivers you might have on your system and uninstall them using the uninstall manager that comes with each one. You can also use programs and features in your control panel to uninstall but try to find the install/uninstall manager first.
*Take the following advice at your own risk and ensure you are comfortable with all instructions before proceeding*
- Go to your start menu and type CMD in the search bar.
- right click on the CMD icon that displays at the top and select run as administrator
- type sfc /scannow and hit enter
- also pays to use a registry cleaner such as CCleaner - Home
to fix any registry files. Make sure you use their backup feature first incase anything goes awry.
At this stage with no other graphics drivers available, windows will revert back to the standard VGA driver. You then want to reinstall the nVidia driver listed above (the same one as the link you went to in the graphics card section of the forum)
If you do opt to do a clean install, I'll try and get a more experienced member in here to explain exactly what drivers you need for your computer - it is highly possible HP lists a bunch of things that are unnecessary.
Good luck and post back with further problems/questions.