Try uninstalling any display driver software and just use the driver.
Try disabling the NVidia Service in services.msc.
Check for newer drivers via optional Windows Update.
Try all available display drivers from NVidia and HP back to and including Vista.
I note you mention "format" as though it's a clean reinstall. Format erases nothing, so if you have boot sector corruption, infection or other corruption the code remains until you wipe the HD with zeroes: SSD / HDD : Optimize for Windows Reinstallation
Other tips for getting a purrfect reinstall: re-install windows 7