Installation of any codec or function always interferes with the external application through the hardware. For instance, a user faced the problem of not being able to find the drive of his external hard disk when he updated the WindowsOS having XP with a service pack. On inserting the flash or USB drive, he could see the USB drive located in the section where device manager is present, but he couldn't see the USB drive in the Windows Explorer of the OS. The drive is located in the disk management section. Once the drive letter is snapped off the connection in the disk management section, the external hard disk is visible.
I installed Windows XP Service Pack 3 Update and now my computer won't recognize my Western Digital External Hard Drive (HD). I tried hooking the HD up to my laptop and that worked, so at least the HD is working. I did a system restore to my computer to a time before the Service Pack 3 update. Still no luck.
I had previously mapped a drive just after my local drives; that is,
..... partition 1 & 2 of the hard drive (C: & D:),
..... CD/RW(E:), and
..... mapped drive(F:).
When I plugged in the USB drive, I could see it in the device manager, but it did not appear in Windows Explorer.
I went to:
The MyBook drive was listed as F:. But Windows Explorer was still remembering my mapped drive there, so I went to the mapped drive F: in Windows Explorer and disconnected. Suddenly the MyBook device appeared. So the lesson may be that some devices want that next drive letter after the local devices, and that mapped drives will not be noticed for some reason, so the machine will assign it there - even though the letter is already taken. But the mapped drive will be remembered.
That was my solution - I found the drive in Disk Management; I went to that drive letter and disconnected (ultimately I moved the mapping down to W:); then all my USB drive content appeared!