arcpy.Describe is not properly running

I run the following code
import arcpy
dataset = r"C:\Script_Data\processing_file\SH_2306.mdb\Working_Personal_dataset"
desc = arcpy.Describe(dataset)
print (desc)

extent = desc.extent
print (extent)
spatialReference = desc.spatialReference
print (spatialReference)
name = desc.name
print (name)
dataType = desc.dataType
print (dataType)

but I got following error massage

raceback (most recent call last):
File "C:/Atool/test/Read_coordinate.py", line 3, in <module>
desc = arcpy.Describe(dataset)
File "C:\Program Files\ArcGIS\Desktop10.0\arcpy\arcpy\__init__.py", line 846, in Describe
return gp.describe(*args)
File "C:\Program Files\ArcGIS\Desktop10.0\arcpy\arcpy\geoprocessing\_base.py", line 372, in describe
self._gp.Describe(*gp_fixargs(args)))
RuntimeError: ERROR 999999: Error executing function.

so how to overcome this problem

chanaka
Sri Lanka