I've lurked in the forums on Joel On Software for a few years, and there is an interesting community of small software business owners over there. There are often discussions or postings about programmes that might interest companies like mine.
One such is Microsoft's MSDN programme for small businesses. They've had something for a few years, and Microsoft recently renamed and revamped it as BizSpark. The intent is clearly to allow a business to grow a need to buy lots of Microsoft licences, but in a way that has no up-front cost for the startup.
Porting my software to Win32 is certainly attractive (perhaps My Own TV Channel could become an intranet tool for businesses), so I've enrolled. Transmission Begins is now a BizSpark partner. Visiting MSDN was like a blast from the past, and I was pleased to see that 'checked' builds of Windows are still made available. I'm now downloading the checked build of Vista to do my initial porting work on. These builds traditionally include more C asserts and such like, to make developing on a closed source product like Windows easier.