After I approved OCX instalation, I waited a lot - but nothing happend.

I couldn't get to the conversion engine window.

I used it previously on a PC with XP OS without problems.

Please help.

Try to disable UAC(User Account Control), 

    http://www.howtogeek.com/howto/windows-vista/disable-user-account-control-uac-the-easy-way-on-windows-vista/

and verify you are logged in as administrator.

I Checked the issue in our lab.

There is a known problem with VISTA & ActiveX instalation (Regsvr32 fail with error code 0x80040200)
I did some tests which didn't solved it (disable UAC, run regsvr32 with WinXP compatebility, login as administrator)

The only thing that solved it was:

- Download the attached ZIP file and extract it.
- Open command prompt as Administrator. (right click / open as administrator)
- Change directory to the filder containing the OCX.
- Type regsvr32 RvControl.OCX + enter.

That should do it.

Guess what???? it actually works....

Thanks