Vista - Vista to ME File Sharing

I am trying to open word files in Vista that are on a seperate computer on my
home network that runs windows ME.

All the folders and files are visible on the network from vista and I can
copy, paste them etc. within windows explorer but just can't open them
directly from Word. Pictures, videos etc open directly from their respective
programs.....

Is their a specific setting in Office that controls security i have to set?
Any ideas on how to fix this?

Thanks,

Neil.