Windows 7: Unable to create image

Since buying this laptop last August i have made regular images into a removable h/d.

Suddenly I am unable to do this.
The data showing states:

Cannot find file (0 x 80070002)

Can anyone suggest how I might proceed.

thanks in advance for your expertise

Have a look at this:
Error code 0x8100002F and or error code 0x80070002 when you back up files in Windows 7

Thank you theog ... I suppose it doesn't matter that I am making an image.
Now it's late and when I tried to read the article my concentration failed so will return fresh tomorrow morning.
I'll return here and post outcome.
cheers!

How would I tell if the computer has a NVIDIA USB EHCI chipset?
Can't find such a code in System, or by using Speccy.

theog and others using Windows 7 image backup ....

It turns out that the only reason I was unable to completea backup image was that I had another item plugged into a USB port. Actually I have a permanent USB hub plugged in so I can use a remote mouse & power the fan in the cooling stand on which the laptop sits. It's handy as I can plug in a flash drive if I want to copy somthing to take elsewhere ...

So inorder to complete backup .... all other items must be removed from USB port!

IF it was a portable HDD it may not have been getting enough power to drive it when connected to the hub.
Particularly, if using a passive hub.

Could be mjf ... that sounds like the simplest explanation so according to Ockham ...it's good!