hey guys im trying to write a simple program for displaying an image using opencv libraries but the program never compiles.. it says no such file or directory 'highgui.h' .. ive tried reinstalling and configuring both devc++ and open cv about twice but to no avail.. ive downloaded the latest version of both DEV C++ and open CV2.0.exe .. sumhow opencv is not configuring the cvcam libraries.. any help will be greatly appreciated.. im just learnin open CV thanx !!

So where is your code and How do you do that?
I would refrain from Long dead IDE like DevCPP and get decent one like C::B or Codelite.
I use CodeLite

Try this example and see if it compiles

// Simple retro-style photo effect done by adding noise to
// the luminance channel and reducing intensity of the chroma channels

// include standard OpenCV headers, same as before
#include "cv.h"
#include "highgui.h"

// all the new API is put into "cv" namespace. Export its content
using namespace cv;

// enable/disable use of mixed API in the code below.

int main( int argc, char** argv )
    const char* imagename = argc > 1 ? argv[1] : "lena.jpg";
    // Ptr<T> is safe ref-conting pointer class
    Ptr<IplImage> iplimg = cvLoadImage(imagename);

    // cv::Mat replaces the CvMat and IplImage, but it's easy to convert
    // between the old and the new data structures
    // (by default, only the header is converted and the data is shared)
    Mat img(iplimg);
    // the newer cvLoadImage alternative with MATLAB-style name
    Mat img = imread(imagename);

    if( !img.data ) // check if the image has been loaded properly
        return -1;

    Mat img_yuv;
    // convert image to YUV color space.
    // The output image will be allocated automatically
    cvtColor(img, img_yuv, CV_BGR2YCrCb);

    // split the image into separate color planes
    vector<Mat> planes;
    split(img_yuv, planes);

    // another Mat constructor; allocates a matrix of the specified
        // size and type
    Mat noise(img.size(), CV_8U);

    // fills the matrix with normally distributed random values;
    // there is also randu() for uniformly distributed random numbers.
    // Scalar replaces CvScalar, Scalar::all() replaces cvScalarAll().
    randn(noise, Scalar::all(128), Scalar::all(20));

    // blur the noise a bit, kernel size is 3x3 and both sigma's
        // are set to 0.5
    GaussianBlur(noise, noise, Size(3, 3), 0.5, 0.5);

    const double brightness_gain = 0;
    const double contrast_gain = 1.7;
    // it's easy to pass the new matrices to the functions that
    // only work with IplImage or CvMat:
    // step 1) - convert the headers, data will not be copied
    IplImage cv_planes_0 = planes[0], cv_noise = noise;
    // step 2) call the function; do not forget unary "&" to form pointers
    cvAddWeighted(&cv_planes_0, contrast_gain, &cv_noise, 1,
                 -128 + brightness_gain, &cv_planes_0);
    addWeighted(planes[0], constrast_gain, noise, 1,
                -128 + brightness_gain, planes[0]);
    const double color_scale = 0.5;
    // Mat::convertTo() replaces cvConvertScale.
    // One must explicitly specify the output matrix type
    // (we keep it intact, i.e. pass planes[1].type())
    planes[1].convertTo(planes[1], planes[1].type(),
                        color_scale, 128*(1-color_scale));

    // alternative form of convertTo if we know the datatype
    // at compile time ("uchar" here).
    // This expression will not create any temporary arrays
    // and should be almost as fast as the above variant
    planes[2] = Mat_<uchar>(planes[2]*color_scale + 128*(1-color_scale));

    // Mat::mul replaces cvMul(). Again, no temporary arrays are
    // created in the case of simple expressions.
    planes[0] = planes[0].mul(planes[0], 1./255);

    // now merge the results back
    merge(planes, img_yuv);
    // and produce the output RGB image
    cvtColor(img_yuv, img, CV_YCrCb2BGR);

    // this is counterpart for cvNamedWindow
    namedWindow("image with grain", CV_WINDOW_AUTOSIZE);
    // this is to demonstrate that img and iplimg really share the data -
    // the result of the above processing is stored to img and thus
        // in iplimg too.
    cvShowImage("image with grain", iplimg);
    imshow("image with grain", img);

    return 0;
    // all the memory will automatically be released
    // by vector<>, Mat and Ptr<> destructors.

>> it says no such file or directory 'highgui.h'

Do you you add the include and library directories to the Dev C++ IDE correctly?