Doyou have an installer? or just the *.ax file?
If you have an installer, the silent switch is /S (case sensitive).
If you just have the *.ax file, you need to use a cmd file with similar to this one:
CODE
@echo off
START /WAIT regsvr32 /s "C:\Program Files\CoreAVC Pro\CoreAVCDecoder.ax"
You can use WinRAR or 7-zip to make an SFX archive. Read the forums to learn how to do that.