I downloaded from official site(hex-rays) IDA, installed, everything works. I found needed for me function, pressed F5(hotkey for decompile so i would see C pseudocode), and got pop-up message:
ida sorry you don't have any decompilers on windows
Can't understand what's wrong and no info about such a message in google i found...
Here is the screen of message: enter image description here
D in IDA stands for disassembler. The free version of IDA does not contain the HexRays decompiler plugin.