Not renewing IP address

Asked before but no replies...PLEASE

Sony Vaio with built in Wi-Fi. Networked with a wired computer on Netgear
WR614. Setup worked fine for months and then I decided to try to add some
security and played with the settings on router setup. Have gone back to the
basic unsecured version. Now in the morning the wired version connects fine
but the wireless version does not connect to the internet until I click
refresh on the
Windows properties box for the wireless connection. When I run "Repair" it
comes back and says "Unable to renew IP address". Then when I click refresh
it connects. It will also connect if I reboot a second time. Any suggestions
where to go (no pun intended) for a fix
Regards,
David

David