In Drive under "Computers", you will have your original backup folder called "My Macbook Pro", the new installation will create "My Macbook Pro(1)". You must copy the data from original folder(s) to the newly created for it to synch down to new computer. *(the folder names may be a bit different depending on how many previous installations of Drive you have, but the end result is you're looking to copy or move data from the older folder(s) to the newly created folders (Documents, Desktop & Downloads).