Guys, thanks for your replies!
GomJabbar wrote:I think I need a diagram.

Here we go:
before: folder -> subfolder level 1 -> subfolder level 2 -> contents level 3
after: folder -> subfolder level 1 -> contents (moved from level 3 to level 2) and no more subfolders at level 2
The bad news is that the subfolders at level 1 are a few hundreds, the good news is that each one of them contains exactly one subfolder (level 2) (i.e. ratio 1:1). I was also thinking of the search trick where one searches for all file types in the contents and then cuts and pastes it in one folder right from the search window, but in this way I will loose the separation of the contents
aaa wrote:I would write a script to do it...
I was thinking of that too, but unfortunately I am script-illiterate

I may well end up learning script language for windows, in a long term it might turn really useful...
Marin
IBM Lenovo Z61p | 15.4'' WUXGA | Intel Core 2 Duo T7400 2x 2.16GHz | 4 GB Kingston HyperX | Hitachi 7K500 500 GB + WD 1TB (USB) | ATI Mobility FireGL V5200 | ThinkPad Atheros a/b/g | Analog Devices AD1981HD | Win 7 x86 + ArchLinux 2009.08 x64 (number crunching)