>>Not necessarily. You may have a thread which does some disk/floppy/other HW operation, and these may use little processor time, so if it happens in a separate thread, the original thread may keep singing almost undisturbed. It doesn't have to wait for the HW issues to get done, so there's still some gain.
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>You're correct on this point. I may have misinterpretted the original question somewhat. And I think others have misinterpretted what I was trying to say. I interpretted the question to be whether or not time slicing was occuring. My response was that when multiple tasks required CPU time, there was always some time slicing that had to occur. (Well, except in cases where a process won't give up the CPU, but that isn't multitasking, now, it is?)

Unless you do something to specifically prevent the operating system from gaining control (such as setting the priority class of a process to real-time, and then never do anything to retrun control to the OS kernel), Windows is always 'multitasking'; it's evidenced by the fact that the task manager can be invoked even when something gloms an ungodly large share of the CPU (like certain operations in VFP can do.) Even with only one application running, and that application inherently single-tasking, there are several operating system tasks running, that provide services even to single-tasking things (liek DOS apps; there's something called the VM86 manager running that handles mapping memory and the like into the DOS application's virtual machine space.)

The Windows Task Manager can give you some idea of what's going on behind the scenes (especially the NT Task Manager) as far as background processes; so can the System Info applet that accompanies Win98. You might want to take a look at some of the reference materials I suggested for Jim; Jeff Richter's Advanced Windows and the Multitasking Overview in the Visual C++ docs in the MSDN give a good portrayal of what multiprocessing, multitasking and multithreading mean; while both sets of references are easier reads if you know a little C, they're comprehensible without detailed knowlege of C and the WIn32 APIs.