my pc doesnt connect to my canon hv30 via hdmi cable

ARe you trying to plug your camera into your video card? Don't. The video card is output and the camera is output. You need an HDMI capture card with an HDMI input to get video from the camera but odd's are you camera either has a memory card or usb/firewire and you can connect it that way. if it's tape based, then you need a hdmi capture device.