Last weekend I had to install three machines with Windows XP from scratch. Purpose was to get them all identical in terms of partitioning, software revisions etc. for a small office.
While all machines have the same hard disks and DVD drives, only one of them has a multi-format card reader that is attached via USB directly to the mainboard. I did not pay special attention to this when I installed the machine; I just went through the Windows setup as usual.
Only when I started installing the display drivers it suggested a path of "H:\Program Files\...", while on the other two machines it had been "C:\Program Files\...". Looking at the drive letters I found out that during setup the USB drives had happily taken the letters from C to F, the DVD drive was G and finally that hard disk got an H....!
I thought of changing all references from "H" to "C" using the registry editor, but then decided against it. After all the whole thing was planned to allow easier maintenance. Fiddling around with some 1000 registry keys right after the Windows install would not really fit into that scheme...
So I installed Windows again, this time disconnecting the card reader from the USB as the setup tool does not allow you to influence drive letters at that time.
And I had already thought that problems with drive letters were a thing of the past...