windows freezing

I bought this Dell OptiPlex 790 for running Microsoft apps (Word Excel and Outlook) and a web browser so nothing much, and wanting to improve it's speed I upgraded the HDD to an SSD (EVO 860). After physically installing the SSD I performed a clean Windows installation. This is where it gets worse.

The OptiPlex 790 has a 2nd gen Intel processor with an integrated graphics card but it being old there are no win10 drivers for it but it worked just fine before the HDD-SSD swap. After the swap it simply used to freeze like in the picture below. If I start in safe mode there is no freezing and works just fine. 

I proceeded to uninstalling the display adapter from device manager and surprise, no more freezes and still can get the 1920 resolution, just not very smooth, nothing that the user can live without. 

But I don't know what gotten into me and I felt like the computer deserves a proper GPU with a proper driver installed and so I did some research on what I can fit into this SFF case and most people chose the GT710 that worked for everyone. I check it on Amazon and as impatient as I am I don't order it from them but go to a store and buy it there so I don't have to way 2 days for it but pay a higher price. I didn't care as I was excited to install it in the PC.  So I change the backplate to fit the SSF connect it cable everything and power on. Everything seems to work just fine, until it freezes a couple of times but then it works and I'm able to install the driver downloaded from NVidia website. And at this point the system is freezing after I type the second character in the login password or even before I select the advance start-up options to get into safe mode. Even froze when I wanted to perform another clean win install. 

I just gave up now and plugged the cable into the motherboard output and disabled the driver and things work again.

I'm just curious if anyone else went through this or if you have any ideas as now im stuck with a GT710 and would like to sort this out.

Thanks.

PS: with the GT710 when it freezes it doesn't look fuzzy like below it just freezes.

fuzzy freeze

Later Edit:

The problem is most definitely hardware, as I formatted the SSD completely and then inserted the GT710 GPU and plugged the monitor into it, then I proceed to install windows and it fails as it freezes in the first seconds after the windows installer stars.

No clue what the problem is as I removed the new GPU and successfully installed a fresh copy of windows with the old one again. same problem fuzzy screen freeze, but disabling the Intel display adapter in device manager fixes the problem. Better to have a working computer with not so crisp graphics than a not working computer.