Hey
@Barry A Chapman, thanks for posting!
Would you mind clarifying which data you're talking about? Did you perhaps enable the computer backup feature? If so, you can find more info about it
here.
Other than that, if you have manually moved files to your Dropbox folder to sync them to your account, these files are still on your hard drive, they just went to the Dropbox folder.
Let me know if you have more questions.