|You need to answer all questions in order for us to help you. Did you work inside the case while the power cord was connected?|
Why did you refer to that hard drive as your logical drive? Wizard fred is correct in #4 above. I assumed you just misspoke but that may not be the case. The second drive may have been part of an array or part of a dynamic disk.
Are the drives in your computer IDE (wide flat cable) or SATA type (round red cable)?
Post the full brand and model of your computer.