HDA Bus Driver

The HDA audio bus driver could be the sound drivers and it could also be referring to the chipset drivers (on a new install the chipset drivers MUST be installed before installing the sound drivers).  There is no SoundMax listed on the Dell downloads for the 755  HERE  there is only one audio driver listed, "Analog Devices ADI 198x Integrated HD Audio" and that is the one you should be using.  I just pointed you to the downloads since you filed to include your Operating System.  Select the correct operating system then download the drivers.

Thanks for the reply...  I tried installing all the audio drivers found in the downloads section but it did not work... I did a little research of my own and I found out that this is somewhat related to the Microsoft hotfix for UAA, I tried installing it, th installer said it was installed but still the audio driver is looking for it.

BTW, I have windows xp sp2

Did you install the chipset drivers?  If not try that and then the sound drivers again.  The chipset drivers MUST be installed before installing the sound drivers on a new install.  One of the main things the chipset drivers do is define what is on or attached to the motherboard. 

The correct install sequence is (1) Install Window (2) Install chipset drivers (3) install device drivers such as sound, video, etc. 

We have found in some cases that if the install sequence was not properly done, and installing the chipset drivers and then the sound drivers does not fix the sound, a new (correct sequence) install is required.

Also make sure the Audio is enabled in the BIOS. You will receive the same "HDA Audio Bus Driver is required" message if the audio is not enabled.