Nokia Software Updater - Error 1720

Hi, I would be very grateful if anyone could help with the following problem:
I have downloaded Nokia PC Suite - this works fine..
When I try to download Nokia Software Updater, I receive the following error:
"Error 1720: There is a problem with this Windows Installer package. A script required for this install to complete could not be run. Contact your support personnel or package vendor. Custom action Kill_process error -2147217407, : Line 5, Column 1, "
Could anyone please advise what I can do. (I am not very technical - so any basic advice would be appreciated!)
I am using Windows XP - Home edition. I have a Nokia 5800
Thank you

If you experience behavior such as application errors or scripts that used to work are no longer working, you may have a corrupted WMI repository. To fix a corrupted WMI repository, you have to reinstall WMI. Follow these steps:
For Windows XP Service Pack 2
Click Start, Run and type the following command:
rundll32 wbemupgd, UpgradeRepository
This command is used to detect and repair a corrupted WMI Repository. The results are stored in the setup.log (%windir%\system32\wbem\logs\setup.log) file.