GTX 1050 not detected on Dell Optiplex 990

[Thodoris_]

I have a prebuilt Dell optiplex 990. I bought a Gainward GTX 1050 and a corsair vs550. I think that the card is installed properly, because its fans are spinning. When I connect the card to the montior with HDMI, I get a "No Signal" message. When I connect my onboard intel graphics to monitor everything works fine. When I open the device manager, there is a section called "Other Devices" and a device called "Serial PCI slot" is in it. I think that this is the gpu. When I try to install drivers, I got a message that says: cannot recognize gtx 1050 (or something like that ). I know I should disable onboard graphics from bios but the option "Video" on bios, is _________ only if the system reconize a GPU (expect the onboard). (bios is : A19 - latest version). Everything is updated to latest version too (chipsets,etc). The slot is not dead, I had a sound card before and it was working fine. The card also is not dead. I've tested it on my old pc and it worked.
Any help?

 

[Thodoris_]

MERGED QUESTION
Question from Thodoris_ : "New GTX 1050 not detected on Dell Optiplex 990"

I have a prebuilt Dell optiplex 990. I bought a Gainward GTX 1050 and a corsair vs550 500w. I think that the card is installed properly, because its fans are spinning. When I connect the card to the montior with HDMI, I get a "No Signal" message. When I connect my onboard intel graphics to monitor everything works fine. When I open the device manager, there is a section called "Other Devices" and a device called "Serial PCI slot" is in it. I think that this is the gpu. When I try to install drivers, I got a message that says: cannot recognize gtx 1050 (or something like that).Bios is not reconizing the card.. When I go to the bios, it says that all PCI express slots are empty.(bios is : A19 - latest version). Everything is updated to latest version too (chipsets,etc). The slot is not dead, I had a sound card before and it was working fine. The card also is not dead. I've tested it on my old pc and it worked. I also opened a thread on the Dell Forum and a guy told me that I should turn CSM ON and Secure Boot OFF but I have no idea what is that and how to do it. I am running windows 10 64bit uefi. I think that the card is supported by my pc. If it is not, I am going to swap cpu from my new to the old pc (they have the same socket) but I have no idea how to and I prefer the dell one...
Any help would be appreciated.

 

[Nightwinq]

did u ever fix it?