Possible problem:

Watch out for capitalization. Try XLConnect in place of XLconnect.

Diagnostic:

You can type library(XLConnect) to see whether the package is actually installed. Unless your installation worked, it'll say Error in library(XLConnect) : there is no package called 'XLConnect'.

Solutions:

If you still have trouble, you may find this page helpful: http://stackoverflow.com/questions/25721884/how-should-i-deal-with-package-xxx-is-not-available-for-r-version-x-y-z-wa

Hi,

I am using R 3.5.3 and I am unable to install xlconnect package. I get the following error:

> install.packages("XLConnect")
Installing package into ‘C:/Users/sansrity_thinkpad/Documents/R/win-library/3.5’
(as ‘lib’ is unspecified)
trying URL 'https://cran.rstudio.com/bin/windows/contrib/3.5/XLConnect_0.2-15.zip'
Content type 'application/zip' length 9831862 bytes (9.4 MB)
downloaded 9.4 MB

package ‘XLConnect’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
    C:\Users\sansrity_thinkpad\AppData\Local\Temp\RtmpUVmLER\downloaded_packages
> library(XLConnect)
Loading required package: XLConnectJars
Error: package or namespace load failed for ‘XLConnectJars’:
 .onLoad failed in loadNamespace() for 'rJava', details:
  call: fun(libname, pkgname)
  error: No CurrentVersion entry in Software/JavaSoft registry! Try re-installing Java and make sure R and Java have matching architectures.
Error: package ‘XLConnectJars’ could not be loaded

How shall I proceed?