Log file for ArcGIS geoprocessing?

Whenever I run a geoprocess overnight, it seems my computer reboots. Does ArcGIS save some log file information? Where does it save it?

For example, when I run a large dataset or image process I need to perform overnight, does it save the logfile that tells you what it performs from start to finish?

Answer

If you have logging turned on, you will be able to see your geoprocessing results in a log file. The "Log geoprocessing operations to a log file" option (under Geoprocessing [menu] -> Geoprocessing Options... in ArcGIS 10 or under Tools [menu] -> Options -> Geoprocessing [tab] in ArcGIS 9.3) will do what you're looking for.

Default locations for these files are C:\Documents and Settings\\Application Data\ESRI\ArcToolbox\History in Windows XP and C:\Users\\AppData\(Local or LocalLow or Roaming)\ESRI\ArcToolbox\History in Vista (and presumably 7).

More details from Esri here.