Where are WU Office updates stored?

I have changed my version of Office but something must remain in my registry
relating to the version which I now longer have. WU has downloaded the
updates before as it shows as 'already downloaded' I 'thought' I had fixed
Office with options found on searching but when I used WU last night I was
once again told the updates failed to install. I would like to delete them
from my laptop but don't know where they are.

I used my install CD to 'Repair Office' everything went fine but when I went
back to WU I got another failed install error - I don't have the applications
now as I uninstalled as carefully as I could without going mad with a
registry cleaner.

I have my install discs but can't fix this problem no matter what I have
tried.
If I could find the downloads to delete it may help me to resolve. I don't
think an uninstall/install would make any difference as it is the previous
version which is causing the problems.

I did look in the registry and found items but would not remove as I am
afraid of corrupting anything. I would just like WU to see the version I do
have installed and not look for things which are no longer there