C:> ppm
ppm> install Name-Of-Module

in case it returns a list of modules, pick up the correct number:

ppm> install 3

There are additional sites with ppm repositories once can find on Kobes Search

Add the repository to ppm and install modules from that place as well:
ppm> rep add uwin http://theoryx5.uwinnipeg.ca/ppms/
ppm> install IO-Socket-SSL 

in ActiveState 5.6.x 
ppm> set rep name URL

In case the computer is behind a company proxy you can configure 
the http_proxy environment variable and ppm will use the proxy:

set http_proxy=http://proxy.company.com:8080