Jerry replaced his hard drive recently and now he's getting Windows Vista update error - Error 8024a000. Leo says that it seems to be an issue with removing the McAfee or Norton AVS that came with the system recovery discs. He recommends removing McAfee. Then once that's done, he should try again to update it. Here's a technote from Microsoft on the error.
The chatroom says it may be a drive size discrepancy and it may be the driver that's causing the issue, requiring a driver update. Here's another technote from Microsoft on fixing it.