Delete or not?
Delete or not?
However, you could have two bootable disks now, and each time you restart your computer you'll see a choice to select the Windows you prefer. If you don't have any crucial files from your username folder on the old hard drive or other important documents, just format the drives.
Type "clean-up" in the search bar, select Windows, then choose Disk Cleanup. It might take a minute to locate system files. After that, select the option for old Windows files or install that can't recall the exact name and click to delete the old installation.
Yes, you should erase the hard drive. You can do this by using a data-wiping tool or a factory reset method depending on your device.
Did you install any apps on the old HDD? It seems you weren’t aware of what you were doing. Clearing or formatting the drives will erase everything inside. If you delete something important, just reinstall the apps. Avoid formatting or writing data to it—use a partition recovery tool to restore the deleted partition and its contents.