Network Adapter Problem

I'm running Windows XP Home Edition SP3 on an inspiron 700m, 1G Ram.  The original 80G hard drive let go a few months ago.  It was replaced with a 120G western digital.  All the drivers were reinstalled but the hard drive is continually clicking as if it is searching.  When the computer starts, it logs on to my network with no trouble and windows is controlling the network adapter.  After it has been running for a while it seems to switch adapters. The wi-fi light on the panel goes out and then it says it is logged in unsecurely and then it goes secure again. Intel Wireless PRO adapter installed.  I uninstalled it and reinstalled and older adapter.  No luck.  If anyone as an idea, it would be greatly appreciated.

Thanks