As I understand it, you can use the keyboard and mouse until Windows fires up. I had this happen on an older version of Windows. Since you know the hardware is working it is just a fluke in the software. Perhaps the drivers for the USBs were not reinstalled. Finding them and reinstalling them can be very difficult.
Originally Posted by alucard
I assume they have their files backed up (HaHaHaHaHa!) This is a good advertisement for using Carbonite or another cloud-based back-up system. When it happened to me, it required a complete reformat and reinstallation and I lost a great deal of data and software.
First, call Dell tech support and ask them what to do. They should have a solution to install the drivers but will probably give you this advice:
Pending a better solution from someone more experienced than I, see if you can back up their files using what's available to you, remove the entire Windows directory and program, then reinstall Windows. If that doesn't work, you will have to reformat the disk, then reinstall all software and files.