Have you just installed Windows again?
Usually this is a combination of chipset and sound drivers.
Go here and download this and run it - http://downloadmirror.intel.com/20775/eng/SetupChipset.exe
Download PC Wizard from my Sig, install it, run it and go to FILE, SAVE AS, CLICK OK and copy the text out of that file to this thread.
What kind of computer is this? The only R52 I can find is a IBM/Lenovo Laptop/ThinkPad. Not a Dell.