Hi,
I've been searching extensively for a possible solution to my error for the past 2 weeks. I have successfully installed the Cuda 64-bit compiler (tools) and SDK as well as the 64-bit version of Visual Studio Express 2008 and Windows 7 SDK with Framework 3.5. I'm using windows XP 64-bit. I have confirmed that VSE is able to compile in 64-bit as I have all of the 64-bit options available to me using the steps on the following website: (since Visual Express does not inherently include the 64-bit packages)
http://jenshuebel.wordpress.com/2009/02/12/visual-c-2008-express-edition-and-64-bit-targets/
I have confirmed the 64-bit compile ability since the "x64" is available from the pull-down menu under "Tools-Options-VC++ Directories" and compiling in 64-bit does not result in the entire project being "skipped". I have included all the needed directories for 64-bit cuda tools, 64 SDK and Visual Express (\VC\bin\amd64).
Here's the error message I receive when trying to compile in 64-bit:
1>------ Build started: Project: New, Configuration: Release x64 ------
1>Compiling with CUDA Build Rule...
1>"C:\CUDA\bin64\nvcc.exe"    -arch sm_10 -ccbin "C:\Program Files (x86)\Microsoft    Visual Studio 9.0\VC\bin"    -Xcompiler "/EHsc /W3 /nologo /O2 /Zi   /MT  "  -maxrregcount=32  --compile -o "x64\Release\template.cu.obj" "c:\Documents and Settings\All Users\Application Data\NVIDIA Corporation\NVIDIA GPU Computing SDK\C\src\CUDA_Walkthrough_DeviceKernels\template.cu" 
1>nvcc fatal   : Visual Studio configuration file '(null)' could not be found for installation at 'C:/Program Files (x86)/Microsoft Visual Studio 9.0/VC/bin/../..'
1>Linking...
1>LINK : fatal error LNK1181: cannot open input file '.\x64\Release\template.cu.obj'
1>Build log was saved at "file://c:\Documents and Settings\Administrator\My Documents\Visual Studio 2008\Projects\New\New\x64\Release\BuildLog.htm"
1>New - 1 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
Here's the simple code I'm trying to compile/run in 64-bit:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <cuda.h>
void mypause () 
{ 
  printf ( "Press [Enter] to continue . . ." );
  fflush ( stdout );
  getchar();
} 
__global__ void VecAdd1_Kernel(float* A, float* B, float* C, int N)
{
 int i = blockDim.x*blockIdx.x+threadIdx.x;
 if (i<N)
  C[i] = A[i] + B[i]; //result should be a 16x1 array of 250s
} 
__global__ void VecAdd2_Kernel(float* B, float* C, int N)
{
 int i = blockDim.x*blockIdx.x+threadIdx.x;
 if (i<N)
  C[i] = C[i] + B[i]; //result should be a 16x1 array of 400s
}
int main()
{
 int N = 16;
 float A[16];float B[16];
 size_t size = N*sizeof(float);
 for(int i=0; i<N; i++) 
 {
  A[i] = 100.0;
  B[i] = 150.0;
 }
 // Allocate input vectors h_A and h_B in host memory
 float* h_A = (float*)malloc(size);
        float* h_B = (float*)malloc(size);
        float* h_C = (float*)malloc(size);
 //Initialize Input Vectors
 memset(h_A,0,size);memset(h_B,0,size);
 h_A = A;h_B = B;
 printf("SUM = %f\n",A[1]+B[1]); //simple check for initialization
 //Allocate vectors in device memory
 float* d_A;
 cudaMalloc((void**)&d_A,size);
 float* d_B;
 cudaMalloc((void**)&d_B,size);
 float* d_C;
 cudaMalloc((void**)&d_C,size);
 //Copy vectors from host memory to device memory
 cudaMemcpy(d_A,h_A,size,cudaMemcpyHostToDevice);
 cudaMemcpy(d_B,h_B,size,cudaMemcpyHostToDevice);
 //Invoke kernel
 int threadsPerBlock = 256;
 int blocksPerGrid = (N+threadsPerBlock-1)/threadsPerBlock;
 VecAdd1(blocksPerGrid, threadsPerBlock,d_A,d_B,d_C,N);
 VecAdd2(blocksPerGrid, threadsPerBlock,d_B,d_C,N);
 //Copy results from device memory to host memory
 //h_C contains the result in host memory
 cudaMemcpy(h_C,d_C,size,cudaMemcpyDeviceToHost);
 for(int i=0; i<N; i++) //output result from the kernel "VecAdd"
 {
  printf("%f ", h_C[i] );
  printf("\n");
 }
 printf("\n");
 cudaFree(d_A); 
 cudaFree(d_B); 
 cudaFree(d_C);
 free(h_A);
 free(h_B);
 free(h_C);
 mypause();
 return 0;
}