Dear All,
I want to downgrade ROUTEROS from v5.1 to v4.17? is it possible?
The main issue with 5.1 is the USERMAN, i copied userman v4.17 via FTP to routeros, then in system packages i clicked on downgrade, it restarts the routeros, but still it shows v5.1.
How can I downgrade userman 5.1 to 4.17 ?
of course you can, Mikrotik is great toys 
maybe this can help http://wiki.mikrotik.com/wiki/Manual:Netinstall
It works the same way as you have upgraded to 5.1.
Just copy the packages on and then “/system package downgrade” (or System->Packages then hit “downgrade” in Winbox) instead of a simple reboot.
(I just had to do this because the RB450G switch part seems to be broken with 5.1)
Have fun,
Andre