Going from PC, word to Mac

I have a Mac OSX 10.5.8, files were transfered to Mac from PC, Microsoft Word, tried to open a file for my book to edit a new revised edition, file opens, can read but canot edit, what do I do?
My wife has Dell laptop and she has the same files, she can open them and edit just fine.

cmd + i on the document, and change the r/w settings at the bottom of the window that comes up. if they are greyed out, click the lock to the right and authorise.

Open Finder, then go to the directory where this document is located, click once and then hit CMD+I or right click and choose 'Get Info'. Towards the bottom of the window that will appear check to see what your permissions to the file are. It should say "You have read/write access" or something to that effect.

If not, ensure that you have write access..

Regards

Amazing how simple this was, I had no idea how to do this, ask the experts and a miracle happens. thanks guys.