When I build a new computer, one of the first things I do is install the most useful free applications I know of. Avast! free antivirus is widely used and tested, and scores favorably against most of the paid antivirus solutions such as Norton and McAfee. Paint.Net is a photo-editing application which makes a near-perfect substitute for Photoshop. LibreOffice is so good at creating Microsoft Office documents I use it to create and update my resume. VLC Media Player allows you to play any music or video format on your computer.  And of course there is Microsoft’s own Windows Live Essentials,which include a blog editor (perfect for updating those WordPress posts!), a movie editor, a mail client with functionality which rivals Outlook, file sync between computers and offline storage on “SkyDrive”, where you can store up to 25 gigabytes of your documents, spreadsheets, music and movies online for free.

There are free software programs for accounting, budgeting, investing and general money management. Some have low-cost add-ons which provide payroll and check-writing capabilities. I don’t use that stuff
so I can’t comment much on it.
Tell me what software you need to use in your business, how
much it costs, and I’ll tell you which free alternatives to try first.