Thanks to advice on this forum I have finally upgraded my old HP1729 desktop, new hard drive(at second attempt) and Windows 7 Ultimate

. All appears to be working apart from I have no sound, when trying to get it going I get the information that the 'peripheral is unplugged'. As the 'soundcard ' appears to be built in to the motherboard I am assuming that it has failed and cannot be recognised. Do I need to find drivers, if so where, or do I now need to buy a new soundcard and fit it to one of the slots, or can I fit one of the usb soundcards if they do the same job. Thanks in advance for any advice.
PS all the drivers are latest and computer thinks audio devices are working ok