I originally used Diskkeeper for disk defragging which had conflicts with PGP, but switched to using PerfectDisk 11 (by Raxco) and after I downloaded and unzipped Raxco's single .reg file for PGP, Win 7 recognized the .reg, updated the registry on its own. I then encrypted the entire disk using the "Use all CPU option" in PGP, and it seems to be working smoothly. My recommendation for Diskkeeper users who may run into problems PGP on any machine is to drop Diskkeeper, install PerfectDisk 11, download and unzip the .reg file from PerfectDisk (Raxco), and then encrypt the disk with PGP. Diskkeeper has a lot of new technologies involving volume shadowing, autodefrag, which actually seem to conflict with their manual defrag -- and involved too much disk activity and tech support to sort out.