It doesn't sound like it could be a virus problem since you reloaded the OS. If someone from the Desktop Forum does not reply, or if bamajim does not see this in a couple of days, you might want to try his website that has tech and malware removal forums. The Tech Staff there is quite good.

Without the PC Model Number and what sound you have we can't give you specific assistance with the problem.

But, the correct and required install sequence is (1) Install Windows (2) Install Dell Desktop or Laptop System Software - on applicable models (3) Install motherboard chipset drivers (4) Install device drivers including video, sound, ethernet, etc.  

We find the chipset drivers are the most often skipped item by users and they are key to a successful reinstall.  The chipset drivers define (identify) all the hardware devices on the motherboard and MUST be installed BEFORE installing sound drivers or in most cases the sound drivers will not install.  Also, Dell sound drivers are needed for most systems with Integrated (on the motherboard) sound such as "SigmaTel", "SoundMax", etc.

Thank you. I believe I have loaded all the items you mentioned above, however I didn't do it in the sequence you describe. I think I did the OS then audio drivers, then the other drivers on the resourcdes disk including the chip drivers. Any way to correct that without blowing the system away and starting  from scratch?

fiveoh 

Hi fiveoh.

Go to Dell Support to Drivers & downloads, stick your PC Service Tag number and download the latest drivers for your sys, use your browser, not Dell download Maneger, then follow Fireberd's install order.

Next time post your PC model as ask by Fireberd, otherwise help is short coming.

Regards.