Defect file in Automatic Update-function

When I try to activate the start the service "Automatic update" on a winXP
pro (sp2) - I get the message that the file is defect (I assume it is
pointing to a "main automatic-update-file". Also if I try to run Winupdate
with the critical choices - I get an error. This error (0x80070002) is
pointing to a solution where I should empty the storage map by running the
cmd; %windir%\SoftwareDistribution. I have tried this without help. So the
defect file for automatic update - obviously has to be repaired or restored
in some way. I am greatful if somebody has any solution.

Regards
Mads