Then it sounds like your PC held the old database. Uninstall Mids', and try following these steps:
If you are using Vista, try going to C:\Users\username\AppData\Local\VirtualStore\Program Files\ and deleting the Mids' folder if there isone in there. That path is for 32-bit Vista. If you are using 64-bit Vista, then try C:\Users\username\AppData\Local\VirtualStore\Program Files (x86)\. AppData is a hidden folder so you will need to enable seeing the hidden folders by pressing Alt > then go to Tools > Folder Options > Click the View tab > then put the bullet next to "Show hidden files, folders, and drives" > click Apply > then click OK. You should now be able to see the AppData folder.
Then do a fresh install of Mids'.