Thanks for quick answer.
It was not a big problem to me to solve it. But why downloader can't tell mi: "you have not enough space on drive x:, check log file c:...\temp\.... for more info." Only Next, Next, Done. There should be some options for more experienced users like old style installators.
By the way.
If you have user profile on separate partition there have to be more than 1GB free space to install flash by downloader.