XP doesn't see External HD in My Computer

XP doesn't see External HD in My Computer

"My XP Professional with SP 3 is not recognizing External HDD using USB cable. I already have two HDD in my computer. One drive has two partition (C: and D:) and Other HDD is F: drive. E: drive is allocated for the DVD Drive.
Now when i try to add another external drive. It does not recognize it. I tried to play with Disk Management but no luck. Any help is appreciated."