Larry,
I just downloaded the R.utils package version 2.7.0 from my local CRAN mirror, and it installed without error (I'm also on Windows 10, R3.5.1, and Rstudio). Did you use CRAN?
If you used the Rstudio "Packages > Install" menu, confirm that you had the "Install dependencies" box checked. R.utils requires R.oo and R.methodsS3.
To get more help you will need to give us more information. Run the following and post the output:
sessionInfo()