It is ok to transfer files, documents but not a lot of good if they cannot be read. When I select a document to read it all my MAC does is show a lot of numbers.

I have just bought a Mac Pro 13 inch lap top. I used migration assistant to transfer from my windows 7 PC to my new Mac all my pictures and documents. Although all the information transferred I cannot read some of the documents. When I click on them my Mac just shows a lot of numbers. I cannot use my Money programme in which I recorded all our bank account transactions etc. I have heard of a programme Parallels desktop 7 for MAC which is supposed to enable me to use Windows on my Mac and also my Mac operating systems. I am concerned that by downloading this programme that I would then have two operating systems that would slow my computer down which was one of the reasons I changed to MAC because my lap top was so slow.