Thanks andresrcs and sorry im new in R.
I successfully downloaded Rtools as recommended.
Here is the output:
install.packages("backports")
Installing package into ‘C:/Users/Win10/OneDrive - Faculty Of Science (Tanta University)/Documents/R/win-library/4.1’
(as ‘lib’ is unspecified)
There is a binary version available but the source version is later:
binary source needs_compilation
backports 1.3.0 1.4.0 TRUE
trying URL 'https://cran.rstudio.com/bin/windows/contrib/4.1/backports_1.3.0.zip'
Content type 'application/zip' length 105005 bytes (102 KB)
downloaded 102 KB
package ‘backports’ successfully unpacked and MD5 sums checked
Warning in install.packages :
cannot delete reparse point 'C:\Users\Win10\OneDrive - Faculty Of Science (Tanta University)\Documents\R\win-library\4.1/backports/libs/x64', reason 'There is a mismatch between the tag specified in the request and the tag present in the reparse point'
Warning in install.packages :
cannot remove prior installation of package ‘backports’
Warning in install.packages :
cannot delete reparse point 'C:\Users\Win10\OneDrive - Faculty Of Science (Tanta University)\Documents\R\win-library\4.1/backports/libs/x64', reason 'There is a mismatch between the tag specified in the request and the tag present in the reparse point'
Warning in install.packages :
restored ‘backports’
The downloaded binary packages are in
C:\Users\Win10\AppData\Local\Temp\Rtmp842Bag\downloaded_packages
library(backports)
Error: package or namespace load failed for ‘backports’ in library.dynam(lib, package, package.lib):
DLL ‘backports’ not found: maybe not installed for this architecture?