The fact that you are using Windows7 is not causing the problem.
I would start by making a backup of your data.
Then run Check/Repair at least 3 times, and see whether it solves the problem.
If the problem remains, export ALL data to a new gedcom file (remove the * from the file name), create a new PAF file with a new name, and import the gedcom file. This will almost always fix the problem. You can then delete the PAF file containing the problems, and use the new one.