Vista - Sharing external drive - mapping problem

I have an external drive H: which I wish to share with another computer. I've set up the sharing from the host and from the client computers. The client sees the drive and can write to the drive. But it won't access the drive when using Vista's Backup & Restore Centre, which is the reason I want to give access to the drive in the first place. Using the Backup, when I indicate the path to the drive, the client prompts for a username and password, even though the option for password access has not been checked. Help!

This article or section includes a list of references or external links, but its
sources ... A mapping layer to other low-level protocols is used to form a
network: ... Sharing storage usually simplifies storage administration and adds
... One of the early problems with Fibre Channel SANs was that the switches and
...

Hi there is some problem related to the backup you did not put the correct location at the time of backup so please take the backup again and connect the hard drive before saving your data to the external hard drive and after completing the backup check the backup folder is showing in the hard drive or not is showing than its all right otherwise you need to take the backup of the files again in the drive and give a name to the backup where you want to store the backup.