>>>>>>>In order to troubleshoot a weird problem I am having, I need to understand something basic. When I Debug my ASP.NET project with Chrome and I enable Developer tool, and then point to bootstrap.min.css file I see it pointing to the following:
>>>>>>>http://localhost:33434/content/bootstrap/css/bootstrap.min.css.
>>>>>>>
>>>>>>>Does it mean that at the time of debugging VS actually copies the bootstrap.min.css to some "temp" folder (physical folder) on my computer? That is, where is this folder http://localhost:33434/content?
>>>>>>>
>>>>>>>TIA.
>>>>>>
>>>>>>In your project do you have Content directory, then Bootstrap, then css? I think this is the place your file it is, not that the project "copies" the file.
>>>>>
>>>>>Yes, I do have this file in the project. But I suspect (don't know for sure) that at run/debug time the .CSS file is copied to Temporary Internet Files folder. That is, I think the VS - when running the project - does not use the .CSS files from the project but rather copies them to temp area and uses them from there.
>>>>
>>>>I don't think this being the case, but try checking that folder in the time your project is run.
>>>
>>>Every time after I clear the cache and then run/debug the project the file appears in the Temporary Internet Files folder. The name is a little different though. It is bootstrap.min[1].css. So VS does copy it there.
>>
>>That's the browser (caching) - not VS.
>
>I see. I am about to give up on IE at all. I have nothing but problems with IE. The latest one is that when I run a simple test form with Bootstrap.css the IE ignores all the Bootstrap rules. The same page in Chrome works. Even when I open a simple page in Fiddle in IE the bootstrap rules are ignored. And the same Fiddle in Chrome works. Very frustrating.

Can you afford to 'give up on' IE - there are a lot of people using it? It has its quirks but it should work OK with Bootstrap although it may be difficult to pin down the cause of the problem in your project....