You can't.
The most you can do is put the database on a server so...
1. It can be downloaded - but then people will have different copies of the database on their local machines which defeats the point of having a database.
OR
2. You will need to completely re-design your interface on a web-platform using one of
PHP,
ASP,
JSP, etc... Since you probably used VB to design your DB interface (forms, reports, etc), I'd recommend you get started with
ASP because it will be the easiest to learn.