Hi, I am getting an error when I am trying to build a library in R for windows . I am using R 2.7.0 in windows. I am following the instructions listed in the R Help for package creation. require(stats) ## two functions and two "data sets" : f <- function(x,y) x+y g <- function(x,y) x-y d <- data.frame(a=1, b=2) e <- rnorm(1000) package.skeleton(list=c("f","g","d","e"), name="mypkg") Then in the command prompt I executed the following command: R CMD build mypkg I am getting the following error : * checking for file 'mypkg/DESCRIPTION' ... OK * preparing 'mypkg': * checking DESCRIPTION meta-information ... ERROR During startup - Warning messages: 1: In library(package, lib.loc = lib.loc, character.only = TRUE, logical.return = TRUE, : ' there is no package called 'NULL in options("defaultPackages") was not found What is it that I am not doing right ? Thanks, Ajay. ----------------------------------------------------------------------------- AVIS : Ce courrier et ses pieces jointes sont destines a leur seul destinataire et peuvent contenir des informations confidentielles appartenant a bioMerieux. Si vous n'etes pas destinataire, vous etes informe que toute lecture, divulgation, ou reproduction de ce message et des pieces jointes est strictement interdite. Si vous avez recu ce message par erreur merci d'en prevenir l'expediteur et de le detruire, ainsi que ses pieces jointes. NOTICE: This message and attachments are intended only for the use of their addressee and may contain confidential information belonging to bioMerieux. If you are not the intended recipient, you are hereby notified that any reading, dissemination, distribution, or copying of this message, or any attachment, is strictly prohibited. If you have received this message in error, please notify the original sender immediately and delete this message, along with any attachments.