If you're looking for a Basic and are tired of having your time wasted by all other kinds of broken and disfunctional software, do not try DarkBasic.
They do offer DarkBasic Professional for free download, but good luck locating it on their website between the myriad of different products and add-ons for sale, and the huge amounts of advertisement.
Still, it's free. Let's give it a shot. Write some code.
And it compiles. But enjoy it, chances are that is an accidental successful compilation. Make a change, and suddenly you get a "Compilation Failed (Syntax Errors)". What does this mean? Where are the syntax errors? Beats me.
I've compiled newly entered source code successfully, made a trivial and undoubtedly correct change, and then gotten a failed compile. Then reverted the changes, and the compilation continues to fail! Searching the DarkBasic forums yields helpful suggestions like reinstalling DarkBasic.
One potential source of problems is that DarkBasic creates new projects under "Program Files" on Windows 7. Then it has no write access and seems to still manage to compile and run (falling back to the temp directory), although leaving a broken project if any at all. But this is actually good, because it is the only way to be able to edit a DarkBasic project without getting the mystical compilation failures after the first change to the code..
I hear FreeBasic is pretty good.