Mark,
thanx for all the links and helps. However - nothing from that helped

1) ten times reset - nothing
2) hard reset (pressing VOL+ and MARK after restrt) - nothing
3) some special script ebook.py script - not even start to run (maybe problem, because I have win7 that uses Program Files (x86) instead of pure Program files ,... ) I tried it in different ways, folders, ... as written here -
http://www.mobileread.mobi/forums/sh...ad.php?t=57906 but nothing helped
4) your idea of stock-fw-updater didn't helped - as PC doesn't see PRS in any way - I installed calibri (old as well as new versions), eBook Library and Sony Reader ... nothing worked to connect the PRS.
I remember that on my old laptop with WinXP it worked ... I will try to connect it there and that will be my last try ...
then I will throw it away ... because of my foolnes (prscustomiser is really only for 505

)