HELP?!?!! 7.3...to 7.4.1 for MAC 10.5.1 ???

[zosick10]

I just want to record something at this point!!

So I am brand new here. 2 days ago I said screw it and wen tout and bought everything I needed to complete my full studio. Of course I bought the new Digirack 003 and went and got a macbook. The mac had 10.5.2 on it and I found out that is not compatible with ro tools at all. So I went back and bought 10.5.1 for another 130 bucks and installed it. The rack came with pro tools 7.3 I found out on this forum that 10.5.1 will only work with 7.4.1. So I downloaded 7.4cs1 which Im not even sure if thats right because I dont know what the cs means. But it wouldnt let me install it because it said it requires the presence on 7.4. So now I have 7.3....I have 7.4cs1 dwnloaded. I need to turn my 7.3 into 7.4.1. Can anyone tell me what to do? I am losing it! Thank very much for your time in advance!