Need disk error checker for Windows XP

I know that XP comes with the Chkdsk program, but I find it lacking in 
one important area...locating bad clusters.  Scandisk for Windows 9x was 
able to scan the entire hard drive for bad clusters (including the free 
space).  XP's Chkdsk only scans the areas that actually have data in 
them.  I find this to be a bit stupid...to put it mildly.  I know that 
Norton Utilities includes a disc scanner, but I don't see any way of 
purchasing it without buying the entire Norton Systemworks 
package...which is a form of evil that rivals even Microsoft.  Any other 
suggestions?