If Strawberry Perl is installed from their .exe file, how can we find out which modules are installed, like LWP, or HTTP?

As usual: perldoc perllocal

Or, if you prefer HTML over the ugly console output, do this:

C:\Users\alex>perldoc -o html -d perllocal.html perllocal
Perldoc (Pod::Simple::HTML) output saved to perllocal.html

C:\Users\alex>start perllocal.html

C:\Users\alex>
[download]

Alexander