i found some information here...
slightly related to your problem:
http://www.eggheadcafe.com/ng/microsoft.public.wi...r/post20558130.asp
i have very little knowledge of this stuff so this information may be wrong..
Try clicking Start, then Run, and running this:
msiexec /x {C3A6819F-62D3-4750-AF1C-28206DDF2C2E}
then click OK.
Edit: i hope it works out for u though