A couple of weeks ago I had an occasional flicker on my screen. I thought I had cured it but it returned and eventually one morning I turned the desktop on and was greeted with a blank screen. The local computer shop replaced the graphics card (Radeon X1600) with an NVIDIA GeForce GT 220. The drivers for the NVIDIA card have been installed onto my XP and my W7 which are on separate drives with a dual boot arrangement.The graphics on both systems seem OK.
However, when I run either XP or W7, I have no sound and device manager says that "No audio device is installed". On XP there is no little speaker on the task bar next to the time and on W7 there is a red cross over the little speaker.
The local computer shop had the machine this afternoon but was unable to fix the missing sound.
I have checked all the cables and connectors for the two speakers and the woofer and the green light on the woofer is lit.
I would be grateful for members' views/comments/guidance/ideas on how to correct this problem.