When I start my Windows 8 PC and connect my LAN adapter, it shows a blank IP in IPv4 properties and hence, doesn't connect to the Internet. Sometimes, if I restart, the IP is shown and it connects to the Internet. What can the issue possibly be?
I think you are saying that the physical connection of your LAN cable is a manual step that you are doing after you boot up (for some unknown reason, instead of leaving it plugged in or at least plugging it in before bootup). Usually, you can force an ip connection without rebooting, by opening a cmd window, and typing: