Do New Amd radeon GPU's work with older Legacy Bios????

I have a dell optiplex 755 MT (biggest model), i have an ocz 120 gb sdd, a q9650 quad core cpu, a 450 watt thermal take psu, and A22 bios (legacy). with Windows 10 pro. and 7 gb ddr2 ram. I bought a new hp oem rx-460 gpu but its having issues. when gpui is installed everything works but when i try to update driver it downloads and looks like it installs but when i try to enter amd settings i get an error, it says driver is either not installed or malfunctioning, i spent 2 days trying to uninstall and reinstall drivers, i even tried a windows reset. when i go into device manager there is a yellow triangle next to rx 460 under display adapter, when i try to update driver from there it arrors stating to go to manufacturers web site. the gpu did work in my biostar n68s3b but wont work in my optiplex 755 mt. from what i recall when i put it into the biostar windows immediately picked it up and updated through windows update and i then went to amd site and installed catalyst and i think adrenalin and it worked fine. now when i go to amd and down load drivers everything seems ok and if asks me to restart, when i restart everything starts up normal but i cant endter amd settings as i keep getting a error message saying drivers are missing or malfunctioning, when i look at cpuid it shows an amd graphicss card but says something like amd basic display or something similar as opposed to saying rx460. when i test it on cinebench i only get option to text cpu, gpu section is blank. ive tried over and over many different ways and still end up with same result. the screen does change and fills full screen when i put in rx 460 and even flickers when i install updates, it even says drivers were installed correctly and asks for restart. but i cant open up adrenaliun or catlyst or even amd setting. originally i thought that the windows 10 auto update was the problem cause it showed that the rx 460 update failed, but last night i got the update to suceed and windows 10 says up to date but still cant get into adrenalin or amd settings. i got code 43 in device manager and it wont update through device manager either. is it possible since i have legacy bios and no uefi that this graphix card wont work, i read mixed revies on this but i have seen many comments stating that they got an rx 460 to work on there legacy bios, am i installing drivers in the wrong order. i tried downloading all windows 10 updates first and then getting amd drivers but still no luck. i tried getting older versions of adrenalin, and in device manager i tried 5-6 differnt drivers, but all wont work properly, all except for a basic amd display driver(cant remember exact name but its something along the lines of basic amd driver, rx 460 is not in its name like it is in all the other drivers that dont work), but this driver seems very basic kinda like a default, cause i still cant enter settings or adrenalin. The only reason im saying this (amd basic driver) works is because in the properties its the only one that does not say error and working properly. is there anyway i can get this rx 460 working on this machine?