General Error message in viewer on final cut pro 7, please help!

I'm new to final cut pro so I don't know a lot about it. I've imported some mp4 footage and some avi footage and both of them bring up this error message when I place them in the viewer & also when I place the footage on the timeline too. How do I get rid of this error message? I read that the mp4 format can't be read in the viewer and that you had to use the compressor so it can be read.

I went onto to the compressor and it completely baffled me. So if you know how to use compressor then please reply too, although I'll need instructions that are simple to understand =)

Thank you in advance.

 

Thank you both for your replies, I've worked out that you can use AVI in the viewer when you click on the clip and then click 'view in new window' in final cut.

I downloaded the MPEG Streamclip and followed your instruction on how to convert it into a Quicktime MOV clip with the Apple Pro Res 422 Codec but when I've tried to import it into final cut it's still bringing up and error message, "File Error: 1 file(s) recognised, 0 access denied, 1 unknown"

When you say create a new final cut project with the Apple Pro Res 422 Codec selected, how do you select that? I opened a new project and then tried to just import the converted clip into final cut and it didn't work. Was this what you meant I needed to do? I may sound thick in asking but I'm new to this and would really like to get a hang of final cut pro before I start a digital film production course in September. It's quite a complex programme to use for a beginner but it is needed for what I would like to do as a career =D

Thank you for all of your help so far. To both of you.