> utils:::menuInstallLocal()
Error in install.packages(choose.files("", filters = Filters[c("zip",  :
  no packages were specified
> utils:::menuInstallLocal()
Warning in install.packages(choose.files("", filters = Filters[c("zip",  :
  'lib = "C:/Program Files/R/R-3.1.0/library"' is not writable
Error in read.dcf(file.path(pkgname, "DESCRIPTION"), c("Package", "Type")) :
  cannot open the connection
In addition: Warning messages:
1: In unzip(zipname, exdir = dest) : error 1 in extracting from zip file
2: In read.dcf(file.path(pkgname, "DESCRIPTION"), c("Package", "Type")) :
  cannot open compressed file 'quantreg_5.05.tar.gz/DESCRIPTION', probable reason 'No such file or directory'
>
上一次下载软件包安装很顺利呀。这该怎么解决，求教了