Thx for answer. I tried installing MinGW 3.4.5, when the 3.4.2 didn't work, but I left old INCLUDE env. variable.

But that wasn't the problem. I found out, that I have to remove path to visual studio libraries from INCLUDE env var, even thuogh they are AFTER the mingw path in the INCLUDE variable. Now the basic libraries were compiled, but it stopped when compiling CLucent support for fulltext search in assistant. I got the same error message as the guy here http://forum.qtfr.org/viewtopic.php?id=6757
but his solution does not work for me... anyway, I think that the rest of the libraries is compiled...