I don't recommend any BASIC dialect for daily usage, it's crappy, but if you really want something like VB, the best BASIC-like dialect similar to it is Gambas http://gambas.sourceforge.net/ (it's only available for POSIX systems right now, so you may be able to run it on Windows if you bought a version of Vista with POSIX support, AFAIK only high end server editions, so you may want to get some real operating system too).
OTOH, if you're serious about programming, you may want to buy some book about Pascal, practice it a bit, and then go directly to a real programming language like C or C++.
-- for those who commented about basic being not crappy --
I have more than 15 years of experience in programming, so don't thumb down unless you really know what you are talking about.
I know those new dialects of basic where "updated" to support new paradigms, and are in fact powerful when compared to the original in some areas, but in the transition many of the most useful features were lost. Also none of these dialects is standard, nor portable.
Back to VB: it is only available for Windows, and only supports PE executable format, which is an nonstandard variant of COFF (Common UNIX File Format), which in turn is an obsolete object format used in many Unices. The current standard for DSOs and executables is ELF, which you can find on any UNIX, and even non-UNIX environments, for example game consoles like GameBoy Advance, Nintendo DS, PlayStation 2 & 3, Nintendo Wii, and many other.
For DB:
* do you know how to write a dynamic shared object with VB?
* can you write games for any of the above mentioned consoles with VB?
* can you link object files against other languages like C++?
* is the ABI standarized?
* can you embed assembler for high performance on critical operations?
* does it support memory mapping of some kind?
About .NET, it's only available for Windows, partial implementations exist for other systems, but only a portion of it is standarized, so important parts like WinForms are unusable (maybe in some future Mono will implement in completely, but it's still non-standard).
Even with .NET you will have the problem of non-standard executable format; you can't mix it with anything else unless specifically targeted for .NET, so you'll need wrappers for anything not included in .NET, which means incompatibility between platforms (so it makes the CLR look like a joke).
Also keep in mind that the development framework is not standarized, so you'll have to make huge efforts to make your sources portable across different implementations.
There are too many disadvantages...
FYI: BASIC is a language for begginers, in fact BASIC is the acronym for Beginner's All-purpose Symbolic Instruction Code.
It made sense in the '80, when hardware was really limited, the standard basic fits that model perfectly, but nowadays we haven't those restrictions, syntactically complex languages can be used on any computer, so there are good alternatives, like Python and Ruby.