multiple APPCRASH events on XPS 410 Vista system

(cross-posted from software section) ...

 

Running Vista Home Premium on a new XPS/Dimension 410 ... have recently been getting a very frequent occurrence of " ... has stopped working" ... it can be Windows Explorer or Reliability Analysis or WMI Provider Host ... have been looking for a solution and have reinstalled a number of drivers (Microsoft KB dowload patches, NVidia drivers, changed from the SigmaTel audio, reinstalled latest DirectX) ... still no solution.  Most events show "faulting module dxgi.dll" ... is there a known problem with DirectX?  How can I roll back to a working version of this DLL?

 

Here's a few of the recent events ... not sure what detail you all would need ...

Faulting application RacAgent.exe, version 6.0.6000.16386, time stamp 0x4549ae49, faulting module DXGI.DLL, version 6.0.6000.16386, time stamp 0x4549bd27, exception code 0xc0000005, fault offset 0x0001fcd1, process id 0x1c50, application start time 0x01c8173ce3528e97.

Faulting application wmiprvse.exe, version 6.0.6000.16386, time stamp 0x4549af45, faulting module dxgi.dll, version 6.0.6000.16386, time stamp 0x4549bd27, exception code 0xc0000005, fault offset 0x0001fccd, process id 0x1718, application start time 0x01c817385c00bab7.

Faulting application wmiprvse.exe, version 6.0.6000.16386, time stamp 0x4549af45, faulting module dxgi.dll, version 6.0.6000.16386, time stamp 0x4549bd27, exception code 0xc0000005, fault offset 0x0001fccb, process id 0x1320, application start time 0x01c817385938ff97.

Faulting application Explorer.EXE, version 6.0.6000.16549, time stamp 0x46d230c5, faulting module ntdll.dll, version 6.0.6000.16386, time stamp 0x4549bdc9, exception code 0xc0000005, fault offset 0x00022a80, process id 0x18c0, application start time 0x01c81736cf4ad667.

Faulting application RacAgent.exe, version 6.0.6000.16386, time stamp 0x4549ae49, faulting module unknown, version 0.0.0.0, time stamp 0x00000000, exception code 0xc0000005, fault offset 0x00000000, process id 0x17f4, application start time 0x01c816a5fb608ab7.

Faulting application nvcplui.exe, version 1.4.900.8, time stamp 0x46e77989, faulting module dxgi.dll, version 6.0.6000.16386, time stamp 0x4549bd27, exception code 0xc0000005, fault offset 0x0002182a, process id 0xc60, application start time 0x01c8169a5bf05a67.

Faulting application RacAgent.exe, version 6.0.6000.16386, time stamp 0x4549ae49, faulting module DXGI.DLL, version 6.0.6000.16386, time stamp 0x4549bd27, exception code 0xc0000005, fault offset 0x0001fccd, process id 0xfc8, application start time 0x01c8169536f36597.

Faulting application Explorer.EXE, version 6.0.6000.16549, time stamp 0x46d230c5, faulting module dxgi.dll, version 6.0.6000.16386, time stamp 0x4549bd27, exception code 0xc0000005, fault offset 0x000228d5, process id 0x1150, application start time 0x01c8169a0c01dbf7.