One thing If the sound advice given thus far dose not cure the issue..
What are the network setting before you remove the device.. is the card enabled or disabled?
what is the status of the ip settings
have you tried, from the command prompt/window, ipconfig /renew
dambed!! when the problem arrises what do you get when you do a ipconfig /all ?

How is the CMOS backup battery? getting a bit old.. could be as simple as the bios forgetting the hardware or being corrupted.. (15%)

The other option is to follow through with IronGeeks tutorial ( www.irongeek.com http://<a rel="nofollow" href="http:...ertutorial</a> ) and build yourself a BArt PE boot CD.. and see what the happens when it boots.. if the network is working 100% run the tools that you have setup on the Boot cd, HJT (save a log before running any of the other tools..dont fix anything..do another log after all else is run.and post that back here), McAfee AV, Ad-Aware.. even Stinger..