XP System Holds on to external USB-connected drive

I need (I think) a utility that will for certain allow me to unplug a USB-connected disk drive from my Windows XP/Pro platform. I have an external hard drive that seems to retain its connectivity under certain conditions, even after I've stopped all "obvious" programs (i.e., those with some announced presence in the task bar) and open up the Task Manager and made sure there were no applications running, and no processes the I think would be doing any I/O. Somewhere, something is latching on to this device and just will not let go.

So, is there a utility? Any other suggestions?

 

Are you clicking the USB icon in the task bar and stopping that way?

 

Yes .... it gives me a pop-up indicating that the device is still in use, but gives no indication as to what process is using it.

 

I'm using Macrium Reflect -- a volume image backup system - to backup my entire system drive (less swap & hibernation files).

On a parallel subject, someone has pointed me to "Opened Files VIew" --- a free utility that shows which processes have which files open, and gives you an opportunity to kill the process.

 

It did not come with any software ... I got an empty case from CompUSA (remember them) and put in an extra drive I had. I used Macrium Reflect, a free (for personal use) image backup utility.

Since the external drive is only 160GB, I have on order a 1GB USB 3.0 package (with adapter) ... however, it also does not come with any software.

I just read Tech Support Alert's comparison of True Image and Ghost. They both cost about the same, and I can get True Image with a 30 day trial, so I'll likely give it a spin. It seems to have a lot more features than Marcium Reflect (which is free). My only concern with any of this is that both my drive "C" and "D" are actually pairs of RAID-1 devices.