hello

1) how do I make mirc window to be "always on top"?
2) how do I make mirc window transparent?

thanks

1) Go to the very top left hand corner of mIRC and left-click on the mIRC icon there. Then check the menu item 'On Top'.

2) You cannot set transparency for the main mIRC window anymore, see this thread.
Transparency for desktop windows can be set in ALT+O > Display > Options > [Windows...] button, then set the transparency per centage (it's the option at the bottom).

Regards,

is there a third party tool to enable me to transparent mirc window?

You can try Transparent Background DLL by -li-. Never tried it although there is some positive feedback.