WDLG Diagnostics 'confused' by Carviar Green 3TB

I’ve been having problems getting this drive to read as 3TB (Windows 7 reads it as 746GB). It used to read just fine, but “something” happend, I don’t know what! There is, or was, data on this drive but I can’t access it with any data recovery programs I have, not even one purported to read “under the system, at drive level” to get at the mp3s. Be that as it may, if there is no way to get the music off, so be it.  Yup, I’ve mostly given up trying to get the data off, but after 3 weeks of trying, I would just be happy to get the drive to read its full capacity again. So, unless somebody reading this has a ‘magic wand,’ don’t worry about this paragraph, just view it as a frustrated guy venting off frustrations.

Now to the crux of the matter: In running the WDLG Diagnostics utility, the upper half (Physical Drive) shows the drive as 3001 GB, but the bottom half (Logical Drive) shows it as 801.43GB. (In case that doesn’t make sense in words, I’ve included a screen shot). I have tried using the WD Acronis utility, but it will not recognize the drive as 3TB. So, here’s the major question: "How can I get this drive to read the full capacity of 3TB??? WDLG Diagnostics discrepancy.PNG

Hello and welcome, 

You need to Initialize the hard drive using GPT. Check the link below for the steps.

How to initialize a data disk by using GPT