Just upgraded to Windows 10 Professional 64-bit.
Upon upgrading, I have completely lost the ability to connect my 5 year old Pavilion dm4 to an external display via HDMI. Further investigation leads me to conclude that *only* the integrated Intel graphics chipset is functioning. The Mobility Radeon 5000 series is completely non-functional, which is why the HDMI functionality is also gone.
I've tried 3 solutions:
1) Re-installing the latest Mobility Radeon drivers provided by HP on my laptop's respective webpage. These graphics drivers are for Windows 7, but at least they were specifically made for HP-style switchable graphics. This solution failed: I get an error stating that the device is not working or the drivers need updating.
2) I installed the latest drivers for my Radeon directly from AMD's site using their autodetect hardware feature. These drivers are compatible with Windows 10, but not for a switchable graphics configuration that seems to be required by my HP laptop. This solution also failed: when I try to switch to an external display, I get an external error message that says no external display can be found (no surprise, because the Radeon is not working).
3) I repeated both steps (1) and (2), only this time installing the drivers in Windows 7 compatibility mode. Alas, in either case I could not get the drivers to install. The installation in compatibility mode would permentantly hang a fraction of the way through the process and never finish.
Does anyone know of other solutions??
I found potential solutions using a BIOS update for dv6 and dv7 systems, but I have neither of those. My system is dm4.
System information:
OS: Windows 10 Professional 64-bit (upgraded from Windows 7 Ultimate 64-bit wi/ SP1).
Product Name: HP Pavilion dm4t-1000 CTO Entertainment Notebook PC
Product Number: WD470AV