Zonal statistics is getting hung up on a 64-bit Windows Vista machine...any ideas?

Discussion created by tiffanyduhl on Jun 3, 2010

My boss and I frequently need to run Zonal Statistics (Spatial Analyst), whereby we calculate zonal averages from 8- or 16-bit interger-type rasters using Thiessen polygons as the zones (the Thiessen polygons basically represent model domains...i.e., some array of regularly-sized cells overlaid over some land region).  The problem is that, on my machine (Windows 7 OS, 32-bit), the Zonal Statistics run just fine, whereas on my boss's system (64-bit Windows Vista OS), the program seems to get hung up depending on the size of the Zonal dataset that we are using to compute averages.  For Thiessen grids >5,000 individual cells, the program freezes.  I've tried different raster formats (e.g. IMAGINE, GRID), and that doesn't help.  We both have an ArcInfo license. 

Any ideas out there as to why my boss's ostensibly superior system can't seem to run this tool?