Problem with windows update, system restore and administrative priviliges

Hi,

I am experiencing three problems with my XP system, which I am guessing are
related:

1. I installed "The Movies" (a popular game) but it won't start, stating
that I have to log on with administrative privileges, even though my user
account does have administrative privileges.

2. When I go to Windows Update, it fails and I get error number 0x8DDD0002
and a message stating I must be logged on as an administrator, even though I
am already logged on as an administrator.

3. When I use the System Restore wizard to try to restore my system to an
earlier state, select a restore point and click "Next", nothing happens.
This is true no matter which restore point I select.

I tried the steps recommended in article 316524
(http://support.microsoft.com/?kbid=316524) but they had no effect.

Suggestions?

mash