Irregular shutting down Fiddler process will sometimes cause block of NIC network access...
Happened 2 times on my work, so should deserve a post to record about this situation.
If one is using Fiddler to trace web application and sometimes Fiddler didn't working well and application is hanging, using task manager to force shutdown of Fiddler process may cause one's client machine's network access behaves weird. symptoms including any web requests outsite the machine will be blocked.
Possible causes of this should be that when Fiddler is starting or terminating, it modified machines connection settings. and if it is shutted down improperly, the machine's connection settings maybe in a corrputing status.
solution for this is to restart Fiddler again and shut it down properly. by doing so modified the machine connection settings back and connection will also be back again.
FYI.
[update]
should be the corruption of IE proxy settings. didn't see that part before I fixed the problem but it feels likely it's the place been corrupted.
