Who knows how to set an option so that traffic of a certain country was excluded from the statistics?
Probably you can do that in for your AdWords account if you have a PPC campaign running. I don't think Google Analytics provides geographical or demographic exclusions that is possible in AdWords.
You can do this as an advanced segment, to see reports that have named countries excluded. Create it from the sidebar, it's under 'My customisations'.Create a new customised segment, from the Dimensions tab choose Visitors, then pick country/territory to add to your segment, and set it to exclude. The alternative is to to set up a new profile, with a filter to exclude the country for that you choose Filter Type: Custom > Exclude Filter Field: Visitor Country Filter Pattern: nameofcountry Case Sensitive: No
The first option yes - with that all you're doing is filtering it out of reports you see when you put the advanced segment 'on', which you do from the advanced segments drop-down menu above where it says what date period you are looking at With a filter, no, as you are actually giving an instruction not to collect to that data. This is why you should always use such a filter in a new profile, and leave a 'parent' profile with no filters, because after you've put the instruction in not to collect that data, you can never get it back.
It works. At least the first method. But I decided to use the second one, I set up the filter and now will see how it will work in the future. And actually there is no need to create a new profile for that purpose, you can just edit your existing profile and there add this filter.
Too late for you now, but really really, ALWAYS use a new profile for setting a filter, because as I said, once it's done it can never be reversed.