ATI Radeon HD 4870 - Will not enter sleep mode

I upgraded a Dell XPS9000 from Microsoft Windows 7 Ultimate to Windows 10 Professional. The update went smooth the exception of the following:

1. Creative Lab X-FI Sound Board - No Sound -- Creative Labs doe NOT have WIN10 drivers yet.

2. AMD Radeon HD 4870 will not enter screen saver mode

This video card is not supported by the latest AMD Windows 10 Drivers.

I am hoping that someone has a possible resolution that will allow me to keep using this video card. The computer was purchased in 2009 and still provides acceptable performance.

I have been able to locate a ASUS Radeon HD6450 video board that might work with my motherboard but I need to confirm the PCIe bus standard.

I am hoping that someone has a possible resolution that will allow me to keep using this video card. The computer was purchased in 2009 and still provides acceptable performance.

Aside from trying older drivers, perhaps in compatibility mode if they don't work properly by default, but it's a hit and miss with older hardware (Your not the only person with an older GPU trying to make it work ).

I have been able to locate a ASUS Radeon HD6450 video board that might work with my motherboard but I need to confirm the PCIe bus standard.

What do you mean by this? Like PCIe 2 vs 3? or the size of the slots on the motherboard??

Looks like I need to look for a AMD Radeon HD7xxx series based on the latest Windows 10 AMD drivers. My Dell 9000 / 435T motherboard has a PCI Express version 2.1 slot and a 460 watt power supply so my options may be limited without replacing some additional hardware.

Looks like I need to look for a AMD Radeon HD7xxx series based on the latest Windows 10 AMD drivers. My Dell 9000 / 435T motherboard has a PCI Express version 2.1 slot and a 460 watt power supply so my options may be limited without replacing some additional hardware.

Try doing what is suggested in this thread:
Solved ATI Radeon HD 4200 driver for 64-bit Windows 10? - Windows 10 blog
Several people with 4xxx series cards like yours have gotten older ccc/driver versions working properly on windows 10.

I got an HD4670 going using 13.1 legacy iirc, only glitch was after I installed 13.1 win 10 update tried to install 15.2 and failed then defaulted to generic win 10 drivers limiting res to 10x12, so I used the roll back option and back to 13.1 with proper native resolution and ccc.

I can confirm that HD6670, 6850, 6870 all work perfectly with recent catalyst.

I removed my Radeon HD4870 Video Card and installed a ASUS HD6450 Silent.

I used the DDU (Display Driver Removal Tool) that was recommended on the AMD blog. After this was done I installed the latest AMD Drivers (Version 15.7.1 WIN10 64 ). The drivers installed without reporting any errors.

I still cannot get the Screen Saver or Screen Turn Off timers to work.

I have the ASUS HD6450 connected to a DELL U2413 via a DVI-D connection.