I have successfully installed 'uniprot.ws'

when I want to load it from R studio using   'libraryUniProt.ws)'

I get this error:

Error : .onLoad failed in loadNamespace() for 'UniProt.ws', details:
  call: file(con, "r")
  error: cannot open the connection
In addition: Warning message:
In file(con, "r") : cannot open: HTTP status was '301 Moved Permanently'
Error: package or namespace load failed for ‘UniProt.ws’

Any comment is appreciated.

You don't give your sessionInfo() output, but I would imagine you are using an old version of R/BioC. Try updating to the latest version, as UniProt.ws loads fine for me:

> library(UniProt.ws)
Loading required package: RSQLite
Loading required package: DBI
Loading required package: RCurl
Loading required package: bitops
Warning message:
package ‘RCurl’ was built under R version 3.1.2
> sessionInfo()
R version 3.1.1 (2014-07-10)
Platform: x86_64-w64-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] UniProt.ws_2.6.0     RCurl_1.95-4.5       bitops_1.0-6         RSQLite_1.0.0        DBI_0.3.1           
[6] BiocInstaller_1.16.1

loaded via a namespace (and not attached):
[1] AnnotationDbi_1.28.1 Biobase_2.26.0       BiocGenerics_0.12.1  GenomeInfoDb_1.2.4   IRanges_2.0.1       
[6] parallel_3.1.1       S4Vectors_0.4.0      stats4_3.1.1         tools_3.1.1