Problem with installing packages

I went back to using Rstudio after several years, so I have a problem with installing packages.
Let me explain: I install packages I need for work, but if I quit the Rstudio, when I reopen it packages previously installed they do not appear, so I am forced to reinstall whenever all packages I need.
I use last version of Rstudio on Windows 10.
Thanks for every suggestion.

This sounds odd. Just to be sure, you mean installing with install.packages() and not loading the packages with library() right? Because the latter is normal behavior.

I use both of these commands.
Is it correct?

You only need to install packages once with install.packages() but you need to load them with library() on every new R session where you want to use them.

I did not use RStudio from several years, I forgot this particular...
Thanks a lot.

Just to clarify, this is not related to RStudio per se but to the R programming language in general.

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