Installing a Western Digitial Internal Hard Drive

WD Internal Drives Desktop & Mobile Drives
4

I just install my hard drive and clone it.

When I rebooted my computer, I noticed that my hard drive letter are this.

Old hard drive OS:C

New Hard Drive OS:E

I want to use the New Hard Drive as the master and reformat the old hard drive.

Can I reformat the the OLD Hard Drive C: and my computer will work.

Any ideas

John