Need Start-Up Advice

I've written a PC operating system, LoseThos, http://www.losethos.com and I'm looking for advice on the next step.

I've had at least 4000 free downloads in the past 3 years, but there is no momentum or buzz. It looks hopeless.

I get lots of hits and downloads when a prominant link is on a site. I'm thinking of advertising, but it seems like blowing money.

Do you think I should seek investors? The fact that there is absoluetly zero buzz, makes me pesimistic. No emails, nothing.