For anyone else with this problem this page should sort it out [URL]
Hi there -- I have an Inspiron 23 Model 5348, connected to a BT Home Hub 5 router running Windows 8.1. Every time I wake the computer up from sleep and often even from booting it up I have no internet connection. I have to release/renew the IP address, and the connection is restored for a while.  This happens on my inspiron whether wired or wirelessly connected. I have upgraded the router, changed the wires, reinstalled the network device drivers, changed the lease time on the router to 21 days and used a static IP address, bit nothing seems to work.  It only happens on the Inspiron. None of my other devices drop their connection. Any ideas what is causing this??
Dropping connection due to IP address release/renew problem