HDD not detecting by PC

[yogihit]

Hi,
I brought Seagate 500 GB HDD (3.5” SATA), with USB case to use for data storage.
I have old PC (P4, 512 MB, 40GB HDD, 1.7 Hz etc. XXP SP3)
Yesterday I disconnected USB HDD and use my MP3 player device for little time and again I tried to connect my USB HDD.
My OS was detecting USB hardware giving some extra warning (Hi –Speed USB installation), it was same before but never problem come across.
Now when USB show as a connected, but my HDD not shown as drive (drive E, F, G etc.) in explorer.
First I thought my USB motherboard drivers may corrupt. I just uninstalled USB drivers and next reboot time it’s installed automatically.
USB drive properly detected in ‘Device Manager’ with my HDD partition numbers too but not in explorer as drive.
I checked it from ‘Mange’ but there are not my disks.
Now I put my HDD as a secondary on different machine (at my friends PC). We change all type of slave options, but HDD not detecting by PC.
In my HDD there are no installed OS so we can not try boot from disk. I am using this HDD as like my data backup.
Please help me out .. other wise I will lost everything near about 250 GB data.

Yours
Yogesh
yogihit@gmail.com

[osprey4]

Hi, Yogesh:

This is a drive letter conflict. Delete your USB devices, reboot and allow them to reinstall. Then plug in your external drive and assign a drive letter such as M, N or O in disk management. Then other USB mass storage devices will not conflict.

This is a general strategy that you should employ for all USB mass storage devices you use regularly.

[yogihit]

Hello osprey4
thank you very much for quick reply.
I tried this very much time but

thanks & Regards
Yogesh