I'm a pretty literate guy, capable of maintaining several computers on a network. The downside of the Wintel platform is that it is a "legacy" box full of potential gotchas. (Those with Apples that never glitch can cast the first stone!)
Recently, I was moving my MOTU MIDI TimePiece AV sync interface, which has served me so well for so many years, from my venerable Pentium 166 to my almost outdated 450MHz PII, connected via the parallel printer port. During installation, a pop-up warning message said the number of active MIDI ports permitted by Windows had been exceeded. Everything but the network card was pulled, the operating system was reloaded, and still the problem persisted.
Conflicts can be caused by legacy devices like Sound Blaster cards stealing resources in DOS but not reporting the same in Windows. (Network cards can be a problem also.) In my case, it was one of the serial ports-Com1 or Com2. I disabled both via CMOS setup, the driver loaded, and the software installed just fine. I cannot yet speak with authority about whether the Universal Serial Bus (USB) reduces legacy headaches, but one can only hope.