EDPnet is currently the only ISP in Belgium to retain the classic dial-up services. EDPnet keeps to servicing those that only require internet occassionally for checking their e-mail. For this purpose, Free EDPnet is provided.
Similar to a classic dial-up subscription from the old days, Free EDPnet requires an analogue dial-up modem or ISDN dial-up modem. Most systems no longer have this by default, although external USB variants (e.g. US Robotics) still exist.
Free EDPnet requires no registration or activation costs, other than the fee you pay your telephone company for the duration of the connection. There are several (national, no longer regional) numbers available for Belgium, Netherlands, UK and France - easy for those that often go abroad and require dial-up access.
More information about the numbers and login details: http://www.edpnet.be/BE-CONS/Products/Internet-at-Home/Free-EDPnet