Cannot install software

Hi!
I really like my ZIRE handheld; I can't go without it.

Recently, I tried to make a backup of my Palm hanheld and
I got an error message telling me that hotsync device (USB)
is not working properly. I uninstalled everything and
tried to reinstall it. Then I've been asked to insert my
win98 SE CD and the installation stopped.

I tried to reinstall the desktop software from the OEM CD
again and again and again... And all I got is this message:

***WINDOWS INSTALLER
This product has damaged configuration data.
Contact your technical support group.***

I went on the PALM web site and downloaded the new
desktop software and tried to install it but I've got
another error message:

***PALM DESKTOP INSTALLER INFORMATION
Error 1714. The older version of palm desktop cannot be
removed. Contact your technical support group.***

Is there something wrong with the registry data?
Can you help me solve this problem? I can't make a backup
of my data and that makes me nervous.