Sony Vegas is not getting my Video files only Audio?

[Geesus]

Hello There,
I have Sony Vegas Pro HD 11 and i'am attempting to commentate games for Youtube using my Xbox 360 and Avermedia Capture card. I have recorded many videos before but never commentated so i decided to commentate and edit the video i placed it into Sony Vegas and it shows the video file only as an Audio file with no video so it plays all the noise and ruckus but no video. How do i get Sony to recognize the video or how do i fix this period?
Help is appreciated.

Thankyou.

[Midnight Blue]

While chris198810's advice may work it's not the best way to deal with your issue. This problem is usually because you don't have the correct codec installed to edit your footage. Find out if that's the case first.