Marianne, You need to convert your PAF 2.31 file before it will open in PAF 4. Start PAF 4. Click on FILE|OPEN. Go to where you have your PAF 2.31 data. Look for a file named INDIV2.DAT, highlight it and click on OPEN. You will then be presented with an OPTIONS screen. During the conversion, your INDIV2.DAT file will not be changed, so you will still be able to use it in PAF 2.31. Select the options that you need from the list. These will depend on how you have entered your data in PAF 2.31. Take particular note of the option to convert NOTES to SOURCES. This will apply if you have used the method outlined by the Silicon Valley PAF User's Group in their manual.