Finally retiring old PowerPro 225 running OS 8.5. Getting a bomb on startup with message that there is a bus error. Will boot with original CD, but won't allow a reinstall, stating that the hard drive is locked. Will boot with extensions disabled, but can't get on network to copy old files to new drive. Have tried Conflict Catcher, but it can't get past the first test. I sense that if I unlock the hard drive, the problem will correct itself. How do I do that? The info box doesn't have a "Lock" checkbox.