Dr. MacDonald, I have searched the archives for Bioconductor and have found that other researchers have had the same problem with getting and installing the HGU133atag probe file. I have not found a satisfactory answer and have spend most of today trying to build and install this particular probe file. Perhaps our lives would be made easier if you would supply us with the hgu133atag probe. I have successfully installed this probe file in an older version. Now I have updated to R 2.2.0 and Bioconductor 1.7 and Windows XP. and these problems have begun all over again. I need to stick to the Windows version. filename <- system.file("extdata", "HG-U133A_tag_ProbeSequence_tab.gz",package = "matchprobes") outdir <- tempdir() me <- "Lana Schaffer " makeProbePackage("HG-U133A_tag", datafile=gzfile(filename,open="r"), outdir=outdir,maintainer=me, version="0.0.1", check=FALSE,force=TRUE) or version="2.2.0"? Successful! # moved zipped C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\Rtmp14299/hgu133atagprobe to library directory Upon installation: #no package 'file8123' was found in: packageDescription(i, lib.loc = lib, field = "Title", encoding = "UTF-8") #Error in gzfile(file, "r") : unable to open connection #In addition: Warning messages: #1: error -1 in extracting from zip file #2: cannot open compressed file 'hgu133atagprobe/DESCRIPTION' Upon trying the older probe package i built earlier: #Error in gzfile(file, "r") : unable to open connection #In addition: Warning messages: #1: error -1 in extracting from zip file #2: cannot open compressed file 'hgu133atagprobe/DESCRIPTION' Lana Schaffer Biostatistics/Informatics The Scripps Research Institute DNA Array Core Facility La Jolla, CA 92037 (858) 784-2263 schaffer at scripps.edu