I have a Dimension 2400 with Windows XP.  I have a legacy keyboard and mouse attached. 
The keyboard and mouse are both non-functional during the reinstall.  This would not be a problem except that a dialog appears during the reinstall requesting the location of a file.  A bit of a problem as the keyboard and mouse don't work!
It would appear that the drivers running during the reinstall are looking for something other than what I have attached for the keyboard and mouse.  Though that seems a bit strange.  The keyboard works just fine during BIOS operation, and during Recovery Console operation.
If you have resolved this problem before, or know how to resolve the problem, I would greatly appreciate your help!