Hello, I am new to Bioconductor and R. I'm having trouble using the Affy library to read *.cel files. I am using the Latin square HG_U95a cel files. I have a cdf file but don't know where to put it for Bioconducter to recognize it(it doesn't recognize it when I put it in R\rw1061 directory. So I tried to download the HG_u95a files from the bioconductor website and it created a folder "HGU95ACDF" with several subfolders. In the data subfolder is a very big hgu95acdf.rda file. However when I run "eset <- rma(Data)" in Bioconductor, I get the message: error in .local (object, ... ) Information about probe locations for HG_U95A could not be found. Try downloading the HGU95A cdf package from ... Which is the package I did download. Does it need to be downloaded into a certain directory other than R\rw1061? Any help would be appreciated. Janet K. Holt, Ph.D. Visiting Professor Section on Statistical Genetics Department of Biostatistics University of Alabama at Birmingham jholt@ms.soph.uab.edu 205-934-2728 [[alternate HTML version deleted]]