Internal WD Drives now showing half of their size

After installing my WD passport se 1 tb … my two internal WD now show about half their size.  The main drive is a WD 160 GB … it is now showing less than 80 GB. My storage drive is a WD 320 … it now show it as a less than 160 GB.  What is going on?  What do I do to get my drives back ?

JimmK

Does the drive capacity remain the same even after the drive is disconnected or does it return to its normal state?

If possible can you post a screen shot of the before and after effetcs?

My Passport is showing the correct size, but my two internal WD drives (160 GB & 320 GB) are the ones not showing the correct size.

The two internal drives remain 1/2 sized after unplugging the Passport.