Still running XP?
Recent ransomware attack show that this is no longer a good idea. However, there is no reason too spend a fortune on a new machine and software.
Free open source software can do just about anything that your computer was doing before.
If you were (or are) using Windows XP, which is no longer supported and highly susceptible to attack, then upgrade to a free, stable and secure operating system containing all the above software.
See the links above.
Running Windows 10?
If you have Windows 10 and get infuriated by its slow operation or updates that refuse to install, why not try an easy-to-use modern operating system that behaves in the way you are used to. You don't even need to remove Windows, just install your chosen Linux alongside and "double boot" - it's easy.
You can try it without making any changes to your machine. See the OS link above.
Running Windows 7?
95% of the machines affected by the recent ransomware attacks were running Windows 7. If you're using Windows 7 and are concerned, then try one of the Linux live cds which will let you try out Linux without making any changes to your machine. If your impressed then you can easily install it alongside your existing Windows setup.
If you prefer to stick with Windows, however, there are excellent packages for Office, emails, image editing, desktop publishing, drawing, sound and video editors and players, music notation input and editing - all free.
See the links above