I use the program 4OnDemand (4OD; www.channel4.com/4od) which allows users to
download programs to watch or to watch streaming tv. Whilst the streaming
function works, I am unable to download anything. On using the repair function
for the program the following message appears:

Error1904.Module

C:\WINDOWS\system32\Macrmed\Flash\Flash9.ocx failed to register. HRESLUT
-2147220473. Contact your support personnel

I have uninstalled and restalled, both Flash9 and 4OD, but it still doesnt
work - any suggestions??

Sounds like 4OD installs an old build of Flash Player... The installer for
Flash Player prevents this if you've already got or had a newer version
installed. If you want a clean slate, so to speak, and want to install the
version of Flash Player that they provide, you'll need to remove the current
version of Flash Player you have and follow the instructions at
http://www.adobe.com/cfusion/knowledgebase/index.cfm?id=4a8d52ae#quote_mark
to allow the older version to install. Whether this will solve your problem
with downloaded content or not, I really can't say. I was under the impression
that they used Windows Media for the downloaded content.