If you right click the network icon in the notification area (windows 7 + 8) you have the option to "Troubleshoot Problems".
This often results in actions like "resetting" (already the first not well defined term imo) the primary network adapter and sometimes fixes connectivity problems.
I am curious what steps Windows actually performs in this process.
Steps i guess there may be included: - pinging default gateway - pinging configured dns-servers - trying to get a new config from the dhcp server - if configured
Maybe someone knows in more detail how the procedure works?