strange problem when opening files

[Guillermo]

When I double-click a word file, windows gives me an error that "The
document name of path is not valid", and the path it puts (the one it cannot
find) just ends before a space in the name of the file. If the name of the
file has no spaces, then there is no problem. And anyways, even if I get an
error, the file gets opened correctly.
So in some way windows is not liking the spaces on the filenames, but only
for word files.

anybody has an idea of what to do?

thanks

guillermo