Download Button on Invoices - Now Saving - How can i change back to opening

Hi

i accidentally clicked the 'download' action button when downloading an invoice and since then all invoices are downloaded instead of opening in adobe reader.
I assume the 'always' do this action was clicked.

ive search the internet and here but see no way to change this back to open rather than download.
Ive updated windows to always open in adobe but with sage it insists on downloading.

can anyone offer any help

thanks
ken