There comes a time in every administrator's life when they need to correlate the information they see within Windows with the information provided by vSphere. In terms of trying to compare Windows volume drive letters with VMDK data store locations, this can be quite a challenge. Sure, so long as all your disks are different sizes, this process is easy. However, if you had a couple 100 GB volumes the only way to determine which drive within Windows you are trying to identify is to delve into SCSI target and bus information.
This script, by Thomas Rhoads, does the heavy lifting for you. Run the script to display the mapping of Windows drive letters to VMDKs on data stores. Keep in mind, for this to work you will need an account with access to vCenter as well as the guest OS instance.