Hello and welcome to the forums allofus992,
If you were wondering if your data on your disconnected drive will still be there and readable on your new OS installation after reconnecting it back, yes it will.
Programs that were installed on the data drive may have to be reinstalled though.
If you get permission errors accessing the data, you may want to attempt the tutorial below to gain quicker access to your files and fix those issues:-
Take Ownership Shortcut