Hi!
every time during starting konqueror system shows notification: install flash. But I won't install it.
My question is: how this notification could be disabled?

This is not a default KDE notification. Can you please post a screenshot of it please, as well as the distribution you are using?

Thank you for your reply.
My OS is Kubuntu 12.04. Screenshots are here http://s2.ipicture.ru/uploads/20120714/kCl4gWAn.png and here http://s2.ipicture.ru/uploads/20120714/DJWsozgy.png.
If option (system settings -> application and system notifications -> other notifications) «restricted codec availability» is disabled and option (system settings -> application and system notifications -> manage notifications -> event source) «system notification helper » is disabled (I mean all types of notification (play sound etc.) are unchecked) there is no that notifications. But it is not a good design because I can not see if any other apps notify me about restricted codec availability. I need to "ask" my OS "forget" about flash only.

I believe these are Kubuntu specific modifications, and would recommend asking about them on the Kubuntu forums.

It's suprise for me. I will post the design on this forum if it be fund.