I was upgrading the video driver for the graphics card in my Dell D420 laptop and ran into the below errors numerous times. The driver that was being upgraded was the Mobile Intel 945GM Express Chipset Family which is the driver for the onboard video controller in the Dell Latitude D420.
Error: “The class installer has denied the request to install or upgrade this device”
The Microsoft Class Installer is what provides the foundation for custom installers. I realized that during one of the reboots during the process I had made some changes to the BIOS settings. These changes were related to USB stuff and what happened is the system was reinstalling a bunch of USB drivers and because the system was reinstalling drivers I was unable to complete the install process of the Intel 945GM Chipset driver. So during the install of the USB drivers there was a lock on any other driver installations taking place.
So once the other USB driver installations were finished I rebooted an attempted to install the graphics driver again. This time I was able to get right through the installation without issue as shown in the image below.
So if you are receiving an error related to the Class Installer I would suggest double checking to see if there might be another driver being installed. Make sure to reboot and then try the driver installation again. I did see a lot of people on the Internet talking about Class Installers for all in one printers and other devices with numerous drivers needing to be installed. I would assume these issues were occurring because so many drivers needed to be installed the actual drivers were stepping on themselves and not being patient when installing such a device could make the problem worse than it really is.