HI 

I installed bioconductor using the following commands 

source("http://bioconductor.org/biocLite.R")

biocLite()

Now to access affy, I am trying to use 

>library("affy")

However it shows me the following error

Error in library("affy") : there is no package called ‘affy’

PLease help.

Regards

Geethika

Try 

source("http://bioconductor.org/biocLite.R")
biocLite("affy")
library("affy")