According to the marketing materials, my notebook as a 120GB hard drive.  Translating marketing GB (1,000,000,000 bytes) into computer science GB (1024 cubed, or 1073741824 bytes per GB) that 120GB is really about 111.8 real gigabytes.  And, that's what the partition table shows for the hard drive.

But that's NOT what Vista sees when it looks at the drive.

That's reporting an 85.2 GB drive!  Where did 26.6 GB go?

In typical fashion, I Googled around, reformated and restored the drive, ran CHKDSK, repartioned, reformatted, restored, and so on.  Windows just won't see more than the 85.2.  Finally, I decided to ask the drive to take a look at itself.  I grabbed a Windows version of the SmartMon Tools.

SmartMon is usually installed as a part of a Linux installation, but you have to install it into a Windows environment.  Modern drives (those made for the past 10 years) have S.M.A.R.T software embedded in their controllers and are capable of monitoring their own health.  The SmartMon tools communicate with the S.M.A.R.T. controllers.

smartctl, the command line tool, quickly reported what's happened.  The SMART attribute "Reallocated_Sector_Ct" reports 8,589,934,592,000 sectors have been relocated.  At 512 bytes per sector, the math doesn't come out to 26 GB, but it's a strong indicator that the drive is in really bad shape.  I guess the time it fell off the top of my rolling bag at PHX and hit the floor hard might have done some damage.

I'm now backing up a lot more frequently and have a new disk on order from Amazon.