Win 2K C drive is seen as plugin device?

Win 2K was loaded on a new 20 GB laptop hardrive and the drive was transferred to an identical machine. Win 2K now sees the drive as a plug-in device (primary IDE channel). The system boots ok, but when a network file transfer is made the data speed falls off to almost nothing. The transfer speed improves to normal as long as the mouse is moved but drops off again if there is no mouse motion. The mouse alters the data speed the same when it is used as usb or ps2. The internal button mouse has no effect. I'm thinking a recovery install in the current machine to avoid confusion with device ids and avoid reloading all the software. Is there a settings fix to cure this problem?