So i recently downloaded the XCMS package through RStudio on Windows. The prompt notes the download was successful and it does appear on the side bar packages list. When I attempt to use the functions from xcms it states the functions are not found. Does anyone have a solution to this.

You don't show any code or output, so we can only make assumptions which may or may not be useful. The best guess is that you have probably not loaded xcms, in which case you will get an error because you have to load a package (using library) prior to using any of the functions from that package.