Cheap Conference Calling

I m using Y! msngr 8., but there is no voice option and pc to pc call. I chkd every menu items. using win-xp?

I m using yahoo messenger 8 on my laptop ACER ASPIRE4710Z with built in mic, cam, speakers. OS is windows xp. all my audio and video devices are working very well in other programs including skype (able to make pc to pc calls). But in Yahoo messenger, there is no voice/call option. I checked every menu item. When i start a conference, there also the option “enable voice for this conference” is dimmed/inactive. Please help me out.
Also checked settings etc., action menu also. I didn’t find any settings related to calls or voice. I also d’loaded DSP true speech codec and copied the unzipped file into windowssystem32 folder. But that also didn’t worked out.

I was also facing the same problem and my problem was now solved. The reason I was not getting any voice/call options in my messenger was that I have installed the messenger for india means the file I downloaded from Yahoo site was msgr8in.exe (as I am living in India), which doesn’t have voice/call options and in conference calls the enable voice option was there but in Inactive mode (one can’t select or deselect that option). When I downloaded the US version means msgr8us.exe and installed that messenger, it is having all the call/voice options and my problem was solved by this.