Audio / video stop working...HELP!

Hello,
I have just bougth on new pc - HP z600 workstation with windows 7 64bit professional operating system. I have install everything i need but now i've notice i'm having a problem with my audio /video programs. I simply can't open video files and with auidio something is wrong too.
Windows Media player, for example is not able to open not even the sample video i have on my system - i gete the "WMP stopped working message". I tried othe programs like quick time, VLC, etc... and something must be wrong with my audio/video codecs.
Can someone help me to figure out what's going on?

This may sound silly, but can you get sound when you click up or down on the volume icon near the time?

That will confirm its not the driver if you hear that small "ding"

Yes i can... all ok with my sound card.
It's most likely a software problem, afftecting almost all my audi/video programs.
Just to give one idea... i can listen musuc with WMP, but after some seconds it crashes and i get the message "WMP Stopped working..."

yea.. seems like it..

try to remove the Windows Media Player (WMP) from control panel.
then try VLC
and after that try reinstalling WPM.. maybe the latest one.
see if that helps.

other thing I can think of is maybe you need the right codecs. chances are less.. but posible

VLC is not working is my system...

I have some new input about my problem:
I've notice that if i open the folder C:\Programfiles\windows media player and execute the WMP.exe file and choose to open some video it works fine!
The problem is that when i choose to open a file with windows media player it will automatically open with the WMP exe file from C:\Program files (86x)\Windows Media Player.
Something similar is hapenning with internet explorer. I get the same message as with the windows Media Player if i open using the icon from Program files (86x). But it works fine with the icon from the program files!
Why is this happenning if i have a 64 bit operating system??????
Please help!
My problem is not solved because i need itunes and quick time to work, and my system don't accept the 32 bit instalation for this programs because it automatically detects that i'm running a 64 bit system, but when i install the lateste 64 bit version it is instaled in the ProgramFiles (86x) folder and i can't run the programs properly!
What a mess this 64 bit operating system!!!

the folder C:\program files (86x)\is for 32bit applications. so it appears that WMP 32 bit works fine for you, but 64 bit is having problems.
One work around is to have the file types like mp3, wma, mov, etc associated with the WMP that is working fine.
but this is not the solution.
Can you remove Windows media player, restart and re-install it and see if that works?

I´m using windows 7. is not possible to unistall it. and is not possible to download WMP 12 for windows 7 64 bit anywhere. I tried many times to diseble it and eneble it in windwos media features, but nothing chenged.

Try this Utility

Try this little tutorial I found this morning:

That was a nice tip. Thank you... now windows media player is working, but everytime i open it i get an error message saying "file error, wronge vts filter", but it abels me to go on and proceed with the video watching.
But that wont solve my problem with other programs. I need quicktime player to your, for example and when i double click the latestest version that i have instaled in my system it wont simply respond.
Dont know whats going on.