I recently installed a new HD and have it as the master drive, with the old drive set as the slave as I move files to the new drive and reinstall programs. For the past two or three times when booting, a screen comes up saying one of my disks needs checking, and I can skip this by hitting any key, etc. I think it says USN indicates a disk may need checking. I allow it go go through all the partitions -- three on the new IDE 500 G drive and 5 on the older 250 G HD -- and nothing is wrong. Is there something possibly in one of the drive's operation that causes this, meaning one is about to fail? This has never happened before with either of my computers. Thanks for your help.