Since you have these problems i would suggest that you turn off your computer, open your computercase and makes sure your NEW hardrive (that you want to install a NEW Windows 10 to) is connected to your motherboards SATA 0 (Zero) and the second (old) harddrive temporally NOT connected at all!
Then you install your Windows (check [REMOVED BY ADMIN] for extra help) and create a ADMIN-account.. and a personal account for yourself (only amateurs use the computers only admin-account) and log on to that account (to create the profile and stuff)
Then you turn off your computer, connect your old harddrive to the highest SATA-connector (usually SATA 5 or 6)..
Start your computer, logon with your Administrative account, take ownership of your OLD hardrive and all its folders.
Copy the folders and files you are interested in saving (not entire disk) to "
C:\Users\Public\Downloads"
Compere the number of files and folders to make sure you copied all contents you like to save...
Then you logon with your own account and copy all the saved files from: C:\Users\Public\Downloads to your accounts similar folders..
And when you are sure you won´t be needing any other personal files from your old harddrive, you use the DISK MANAGER to erase all partitions (begin with the one to the right and work yourself towards the left until all are erased) then you create ONE partition and format that one With NTFS... So you may use the entire old disk as storage!