Some display problems on an old nvidia graphics card

Hey everyone!I have some problems while using Linux(not only on openSUSE) with an old nvidia graphics card.I used to use Ubuntu Kylin,it uses the UKUI desktop environment(based on MATE).At that time there were no problems at all.But when I want to change a desktop environment,problems appear.
When I use Ubuntu desktop(and GNOME 3),I can’t change the resolution.Every time I change,the computer will “die” and there are some color blocks on the screen.Then I installed a KDE desktop.I used lightDM instead of SDDM,so I need to go to the tty to unlock the desktop.But every time I came back,the text under the icons can’t show normally.
Now I am using openSUSE.But when I turn on the computer after sleeping,something on the desktop “changes”.The colors on a widget change.
I have installed the close source graphics card driver using package manager.So why these problems happen?

And the package manager tells me to uninstall the driver when I runs “sudo zypper dup”.

The following 2 packages are going to be REMOVED:
  nvidia-gfxG02-kmp-default x11-video-nvidiaG02

2 packages to remove.
After the operation, 181.2 MiB will be freed.

Oh,sorry I forgot.My graphics card is Geforce 7900 GS.And I can’t use the graphical installation.Only after installing closed source driver can I use KDE(except on Linux Mint liveCD).