Try it on another PC.
If it works there, you at least know the device and drive are good and it's something with your machine.
Dell sometimes does special configurations with it's OEM OS. Some things you could try if it works on another machine.
-Check USB settings in BIOS, legacy or auto (hit F? or DEL at boot)
-Turn off Windows and any other firewall or security software before connecting.
-Try a USB port on the back of the machine.
-Make sure the User Account you are logged into has Administrator privilages
-Jumper setting on the drive may need specific setting, usually master or cable select (change while powered off)

(I'm also assuming the old drive had another version of Windows on it and that it was not encrypted)

I hope that is helpful,
Good luck