HP Pavilion has two Factory Recovery drives

Have a client with a Pavilion P6310y running Win 7 Home 64 bit.  He keeps getting a "low disk space on Factory Image (H)" but he also has a Factory Image (D).  We don't know when or how the other FI drive was created nor why it is giving the warning.

I'm assuming the D is the "original" factory image and that the H is a duplicate...?  Not sure.  Can anyone please first address:

1) Why there are two FI drives?

and

2) What may be causing the low dis space on the H drive

and

3) Can I delete or clear off one of these images and if, which one?

Thanks!!!!