Upgraded my XP Home pc hard drive to 500Gb. Used Acronis Drive Image to copy the existing 250 Gb drive. Installed the new drive as C: and left the old one as E:. Everything worked fine until my grandsons complained that the EA Medal of Honor and Novalogic Delta Force games would not run. After all the usual steps including reinstall, without result, I tried running the games from the E: drive (old C Result! Perfect game operation! My question is why? How can the system tell the difference if the drive copy is exact? Anybody out there who can tell me as it is bugging me?