Version conflicts for Outlook and Excel ?

I have Windows XP. After installing SP2 (I suppose) Outlook (Office 10)
crashed frequently and changed my task bar. So I tried to update Outlook.
Somehow I managed to install some updates, though my license should not allow
it. Eg in Info 10.0.4219 -SP2 was shown, but in the appliaction error
10.0.4024. EXCEL worked fine.
Then I read there might be a conflict with Office 2003 (I had installed
(only) Front Page 2003 in the meantime.) So I uninstalled my FP2003 by the
system "control" option (translated from german).
After some other automatic Windows XP updates, Outlook almost every time
reports errors from the mail server, that it will not accept connection, but
nevertheless sent mail goes through - some times even twice. Excel was fine.
Since there was no success in removing FP2003, I installed it again. Now
Excel does not allow me to open the xls-files without installing it again via
Pro.msi. But I have none. I have bought a PC with a fixed installed Office
2002 (Office10) package.

How can I get rid of my version conflicts ?
Many thanks Michael