At this moment in time I have only the Vista Codec Pack v.437 installed
because it lets me play most media files in Windows Media Player.
The biggest problem remains the mpg-files that I made with my Sony DSC-755E
photo camera on Memory sticks.
I copied the mpg-files from the Memory Sticks to my hard disk.
On my old machine, Windows XP and WMP 9-10-11 read them perfectly.
With my new (much more recent/powerful) machine, Windows Vista Home Premium
and WMP 11 can't handle them anymore (progress ?).
I have had the VLC player installed on my machine (I was wondering if that
would work) and it gave me the sound but not the image. That is why I have
uninstalled it.
I'd love to do the needed basic things (and even more than that) to make it
work you know Adam, but I am hoping that someone is going to tell me in a
basic-language what I should do and how

.
Thanks for the help so far, and hoping for even more help.
Because I really would like to make this work.
Being in a playful mood I downloaded and installed the Vista Codec
Pack you mentioned and as soon as I did, then I had the same problem
you did. That strongly suggests that is the cause of your problems.
One or more of those codecs is giving Vista a bellyache. The odd thing
about codecs is they may mess up some systems and not always mess up
others.
Try this. Do a Goggle to locate the "Microsoft XP Video Decoder
Checkup Utility" and install. Its just a little utility that will work
under Vista. See what it nags about in the way of MPEG2 codecs. If
some are giving Vista a bellyache is should put a white x inside a red
circle similar to how Device Manager nags about things on your system
giving it problems.
Next write down the list of codecs with the x, locate them on your
system, should be somewhere in the windows folder on your root drive,
unhide these files if necessary, then ONE BY ONE try renaming the
codecs Vista don't like. Then after each change, do a reboot just to
make sure the change gets registered and see if it helps. If you get
past the problem you can either just leave the problem file or delete
it once you try playing all the file types your normally do to be sure
it isn't being used by something other than Vista. Remember most
video/audio applications like to install their own codecs and may not
always put them where you expect.
If that don't help, try a better tool that lists more codecs, ActiveX
filters and other things Vista uses to play back video files. One very
good one is GSpot. It too is small and free and can help you track
down what's wrong.