This is my first post here and to be honest this is my last hope. I recently rebuilt my Windows 7 SP1 64 bit based PC with a new ASUS motherboard, a 8350 CPU and a 8 GIG RX480 also ASUS branded, it's nothing fancy but serves me well enough. I am using a 1080 display via HDMI and have updated Radeon Crimson to the latest edition, 17.5.1 at the time of writing.
When I first got the system up and running again I installed some of my older games like Starcraft 1, C&C Tiberium Sun and Red Alert 1&2. These ran fine but later on all of them refuse to open a screen or just crash to desktop and report they cant open a screen. I tried updating my drivers to the latest version but it didnt help. This same behaviour is now happening with Galactic Civilizations 1&2 also. More modern games still work fine so it seems to be only be effecting these older games. I've tried every compatibility setting I can and tried editing the preferences files for these game (where possible) to run in a window to no avail.
Am I missing some setting I need to apply to my graphics card driver or is there something I need to disable to allow these older games to open a screen? Some of them run in the background but the display isn't being picked up by the HDMI port anymore. I have also installed all the updates from Microsoft so my PC is also upto date with regards to other drivers and service packs.
Any advice would be appreciated.