Windows drivers do not work with Linux. Ubuntu (Linux) uses it's own drivers to make hardware work.
Without knowing what make/model system that you have, it is hard to guess what the issue might be with the video and sound.
If you are using as self built system, posting the motherboard make and model would help folks troubleshoot the issues.
Also, you are using an older version of Ubuntu, so if you have a relatively new system, then this may be an issue.
the Ubuntu wiki page for your version may be of some help to get you started. It is located
here.
Try the New to Ubuntu 8.04 LTS? page first.
Post what you have done to try to get the resolution changed.
Have you turned up the volume to 100%? Post what exactly that you have tried, so folks can get an idea exactly where you are at.
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"I love it when a plan comes together." - Hannibal Smith