scratch disk

from The Free On-line Dictionary of Computing (8 July 2008)

scratch disk

   1. <storage> See {scratch}.

   2. <operating system> Unallocated space on {Windows 95}'s
   primary {hard disk} {partition}, used for {virtual memory}.

   Shortage of space on this partition can result in the error
   "scratch disk full".

   (2000-03-07)