I have just migrated to a new Win 7 system. Fresh install of PS CS4, I found I could load CR2's into ACR but not jpg's. Wehn I tried to check Camera Raw preferences in Bridge I got message "Camera Raw not enabled...." even though PS had been started several times. I tried to update to ACR 5.5 but got same message. I installed it manually as per instructions but still same result. Cannot load jpg's into ACR. I do not have this problem on two XP and one XPx64 systems.