On the old computer, open ProSeries and highlight all your client files. Choose File > Client File maintenance and Copy/backup all the files to a flashdrive.
Open ProSeries on new computer.
Click File > Client File maintenance and choose Restore. Highlight all the files on the flashdrive and restore to the new computer.
Now run the Homebase Database Maintenance, that should sync HB up.
You'll then want to open the EF Center, highlight all your client files and choose to Update Selected Acknowledgements to pull all the EFile information into the new computer.