Generally speaking when doing a clean install, all the data is lost. It's recommended to save any data one wants to keep before doing a clean install.
Note: When doing a install of any kind, the drive affected is the C drive which is the default drive assigned by windows. So any other drives should not be affected, unless you have partitioned the C drive. If this is a retail PC/laptop, the D drive is the hidden partition which contains the recovery partition to restore the device to factory condition. A clean install will wipe all this all this out and recovering the data is next to impossible.