the 7600GT was supported by debian (I am not sure, if it still is with the
actual kernel).
At the moment it is supported by the kernel module "nouveau", but when you
need hardware acceleration for i.e. games or other applications, you have to
install the driver from Nvidia.
To do this, there are several ways:
1. install the old legacy packages from debian
You will not find the debian packages in the actual repo, as this card is too
old. Ther eis a special repo, where you can find these packages, (I am not sure
and maybe someone will correct me), it is called "backports.debian.org".
Please note, that the kernel module always has to be build and as far as I
know, these old kernel modules might fail at build on newer kernels. This is a
problem with the gcc-version, the environment and the kernel heraders itself.
Maybe you might have no other choice, but to run an older kernel, which might
cause other issues.
2. download and install the driver directly from the Nvidia site
You may try to install the drivers from NVidia site. However, the kernel
module has still to be build, but that may also fail with the actual kernel.
Same problem as above.
As for VLC, the problem is known. This is a graphics driver problem. I guess,
that you are running either the vesa driver or the nouveau driver, which both
lack of 3d-acceleration. You can try to change to another driver in VLC
setttings (maybe "x11" or another) but avoid opengl. With a hardware
accelerated driver like the propietrary driver from nvidia, setting "opengl"
is recommended, if there is none, try "x11"
Same is for resolution, it is a driver problem. The nouveau driver is running
well with resolution, but you might need an "xorg.conf" to force the required
resolution. Xorg.conf is no more needed and disappeared from debian some years
ago, so you have to edit your own. I personally (and here people might not
agree with me), prefer a xorg.conf so I have the advantage to set exactly what
I want.
Solutions? Don't know. If possible buy a new cheap graphics card. Nvidia will
be my first choice, Cards like GF 240 or similar are 20-40 € (running with
actual nvidia-legacy-390xx*.deb). Or, if you want to spend more money, buy a
modern one.
If you cannot, because this card is soldered within a notebook, think of
installing either vouveau or an old proprietrary driver from nvidia in the
price of an older kernel or try to get it compiled for the actual one. The
drivers from Nvidia (which is a *.run file) can be unpacked and singly build.
If you try the packages from backport, you might also install the old compiler
environments, which might break your system. Solution (but a lot of work), try
to install all the necessary files, then build the kernel module, aftrer that
reupgrade your system. Take care not to deinstall your Nvidia-packages during
this step.
Well, it is all not easy, but I hope, this helps!
best regards
Hans