How long to initialize? (about)

I have an XPS600, 3.-somethingGhz Pentium dualcore, 2 gig ram and am installing a 500 gig western Digital serial ata drive. I am using it with one partition as a storage disk.

Is there a ballpark time I can expect the initialization process (using disk manager) to take? It has been "initializing for 18 hours or so now and by everything I can see, is doing just that. The computer is not locked up, everything functions and I can see CPU usage of around 44% with small variations, (nothing else running) like it really is doing something.

I'd hate to interrupt this only to find out this is how long it takes but I can't find anything that gives any indication of how long it might take.