When to file a patent?

The best rule to follow is to always file a patent application before any public disclosure or use of the invention. To gain protection in different countries, you need to secure patent protection in those countries. PCT is a great means to achieve a patent in blocs of countries, particularly Europe, but you still need patents to protect your inventions. So, for example, if you file in the US first, you have one year from the US filing to file a PCT application - then you have, usually, 30 months to file particular applications in particular countries, although some countries vary as to the filing times, so you need to check for the particular countries that you are interested in.