win 2K - download ok, install KO

Dear all,

I would like to install critical updates on an old pc running win2K
french.

I just installed the following (without using windows update):
* Service Pack 4
* Update rollup 1
* IE6 SP 1
* Malicious software removal tool

If I launch windows update, he locates and downloads 2 critical updates
( B I T S, win installer 3.1)... but after download, says the updates
could not be installed.

I tried several times, emptying temp internet files, ... Always same
error.
Event viewer is empty.

How can I see what happens?

Cheers,
Alain