Hi, I will try to help. Firstly how many files are we talking about not opening? Also do you still have them on your old PC? How did you transfer the files from the pc?
The Apple store transferred all of these documents and I used to be able to open them. I probably have around 1,000 old documents and only about 12 of them have this problem. They are not on my old PC any longer. Here is an example of the name of one of the documents:
GGG - 2007 Extended Schedule.doc
Like I mentioned before, they all have a date of April 28, 2013 when they were last modified and/or opened. To my knowledge, I didn't do anything to cause this.
Does each of the 12 files have a small arrow in the bottom left of the icon? (which would indicate a normal alias) Also how big is each of the 12 files, highlight a file and press command i to see the size, a normal alias is about 90kb) Do you have any pc you could email a file to, to see if it will open?
Yes, each of the 12 files has the small arrow in the bottom left of the icon.
Each of the files is exactly 133 KB.
I do not have a PC at this location.
I just emailed one of the documents to a friend to see if they can open it.
OK, the small arrow means it is an alias and all aliases on your mac much be 133kb. I'm afraid the mac wont be able to open your file, nor will any other computer. You would have to go back to the original but you have said they are not on the old pc any longer. Your only chance is to use a file recovery program on your old pc to try and salvage them. I'm sorry this is not the news you wanted to hear.