If it works ok, add the floppy drive and try a boot disk. If this doesn't work, I would try booting with just the basics: CPU, power, video, and keyboard.
I would check all cables and make sure they are seated well and in the right direction. It is probably worthwhile to make sure the video card is seated well and that the cable is connected properly, but it may be referring to another cable such as the IDE cable that goes to your CD drive or hard drive, or even your floppy. The reference to 'Media failure' doesn't necessarily refer to the video.
