Hi. I have been working on a Dell Inspiron 531S and am unable to get the video, and now audio, drivers loaded and working correctly. Here’s the deal: According to the Dell tag# info online, this cpu uses either the onboard Nvidia nforce 6150SE n430 video card or an ATI 1300 Pro. There is no external video card so the Nvidia should be right. This is confirmed by programs like HWinfo32. However, someone did install ATI catalyst software at some earlier point. At first, only the video card driver was not loaded properly and so Vista (Home Premium 32-bit) was in VGA-compatible mode. I tried to load NVIDIA Nforce 258.96 WHQL drivers for Vista 32-bit, which completed without errors. Upon rebooting, though, I could see in Device Manager that the drivers didn’t take. I have also tried Dell’s recommended R166208 (an executable that loads Nvidia’s MCP61 ver.A01 drivers) and no matter what I do, Device Manager says I now have an “unknown device” or a VGA-compatible display adapter. Unloading and reinstalling did not help. I noticed SP2 was not loaded so tried installing it to see if that would help. It loaded no problem, but then I saw (as another update) a Realtek audio driver update. I let it load and now have no audio. I have tried both Dell’s recommended Realtek driver (R180772, which is for the ALC888 HD audio device and loads Realtek’s R1.85 audio drivers) and a newer R2.51 version for Vista that I got from Realtek’s site. Both install fine, but rebooting results in Device Manager disabling the Realtek device. If I enable it, it wants to reinstall drivers. But doing so either fails (when trusting Windows to do it) because it says I already have the correct drivers OR I can load them, reboot and find the process happening all over again. It always tells me there is no audio output device installed. So far, I have updated the BIOS, run Driver Sweeper to clean out all ATI and NVIDIA display and physix drivers as well as all sound-related drivers and tried the above in Safe Mode, as well. Nothing works. I am at a loss. Both devices are acting as if they are disabled somehow, but I see no reason for it in the BIOS or anywhere else. Ugh! This is very frustrating. If anyone can help, I would really appreciate it. Thanks.