Resetting network adaptor

[#1]

Running Vista and whenever I go into Network and Sharing Centre to check the settings, the wireless goes to local only so can't connect to the Internet. If I click diagnose and repair it comes up with something about dns and contact ISP so doesn't get repaired. Switching off router and re-booting computer didn't work this morning but I went into Network Map and reset the network adaptor and this worked so am now back on line.
I have googled it and made some notes from Microsoft but don't understand this fully. Why does the computer do this? It only happens when I explore the settings. What exactly is happening? Hope someone can explain (simply).

[#2]

Hi
try this plz, Vista DNS. when you are in step 4 plz try it on the wireless instead of the Local Area Connection.
if this didn't work, you might need to check if your wireless adapter drivers are up to date and/or wireless utility as well.
I had almost the same problem with my Laptop, but fixed after updating windows which has downloaded a new Microsoft digitally signed drivers

[#3]

Its down to the stupid profiles in Vista you have a profile for local only and one for Internet. You may have more of coarse if you travel and connect to other networks.
Its a pain as it can switch without warning and leave you in the situation you are in all that is needed is to swap back to the other profile. There is a free util that makes doing it a breeze see
http://www.techmixer.com/switch-windows-vista-network-setting-easily-with-net-profiles/

[#4]

Thank you for the advice gentlemen - I have bookmarked the links and will take time to study and hopefully understand them later.
I think that Samuria is right about the profiles because when it goes down I put the ethernet cable in and it still doesn't give me access to the web. I find it all a bit complicated but am determined to get to grips with it. A simple thing like checking the wireless  settings etc shouldn't send everything haywire.

[#5]

Rami - have just printed off the instructions as per your link and will follow them if/when it happens again. Thank you for that and will post back later as I will have to recreate the problem before following the procedure. At least I now have an idea what is happening, which is reassuring.