Software sales?

If you are new to the software market, you could make a free version with limited features of your software. Free stuff will spread fast over the internet.

Use a reliable cloud hosting service instead of managing everything in-house...

Find a problem people are having which you can fix.

Do you have a focus on what kind of software you like to program?

Niche down a bit.

What about Windows software do you usually fix or improve?

An example: in business, many companies use different programs to manage their inventory, accounting, and CRM.

Often, these don't communicate with each other well and errors occur. What was shipped wasn't what was recorded as taken from inventory, and so now Billing is wrong. The customer gets an invoice for the wrong thing. This results in slow payment, back-and-forth talking with the customer, and perhaps raised tempers.

Some software devs concentrate on bridging these gaps and getting the different software packages to talk to one another. List some specific programs and now you have a niche.

Where will you concentrate?

You can ask!

Ask your buyers, or decision makers in a target market you're considering.

Never build anything just because you think it's a good idea--get confirmation from buyers that they will pay for the solution first!

I've written my own MS Office software and sold thousands worldwide for around 9 years.
I used free to list software sites in the beginning but the last two years I branched out a little and have a Facebook fan page which picks up around 20 fans each week without any work needed on my part. My shopping cart company also does promotion worldwide of software registered with them. I would advise setting up a website where you can give away a cut down demo version of the software. Inside have a button that takes them to the shopping cart to buy the full version. Or you can list both demo and paid versions on the website. To bring in more traffic I used YouTube and tutorial sites such as tutorialized.