In this day and age of drive-by download based attacks (when the ransomware got you was it from an email attachment or a program you downloaded which claimed to be something else, or was it out of nowhere just from visiting a site? i would guess it was the latter) perhaps your best defence is the firefox browser extension/add-on called NoScript, this prevents sites running anythign except basic and safe html code unless you specifically allow it. It makes almost every type of browser exploit impossible, the only cost is that when you want to do more than browse (such as watch a video, or on some sites login or make a comment)then you will sometimes need to make a few extra clicks to allow particular pieces of content to run, you can select those you allow so only the site you are visiting can run things and content cannot run from within adverts. You could also install Ad-block plus alongside it to avoid adverts, many of which spread malvertising attack these-days.
You should keep windows up-to-date, but in the light of certain updates causing crashes and others trying to forcibly upgrade users of windows 8 to 8.1 you should set updates to check automatically but let you shoose when to install, that way you can give it a day or two to hear if others report problems with a particular update. The updates named "Security Update for....." are the most critical and should be installed as soon as possible, the update called "Update for..." can wait a little longer so you can be more sure they don't have bugs before installing. Browsers and flash/java plugins should be set to update automatically, checking automatically on atleast a daily basis.
You should scan with your antivirus and your anti-malware program EVERY file you download before you open it. You should turn on "display full file extensions even for known file types" in "folder options" in the file browser so that you can spot any exe files pretending to be other formats, you should never open an exe file unless you are absolutely certain it is safe as this is generally the format which carries viruses, the only time you should download exe files is when installing a new program.
You can use CCleaner to disable items from your startup, this isn't always security related, it can help performance too, but it is useful to know, dusbaling means that if an item turns out to be important it can be easily re-enabled. CCleaner can also help you dispose of temp files to keep your computer running reasonably quickly.
Although NoScript should protect you effectively, it is wise to check sites you are unfamiliar with by typing their URLs into web of trust and seeing what reviews people have made of them, although such reviews aren't always reliable.
If you feel suspicious about your machine ESET online scanner and kaspersky virus removal tool are good on-demand third opinion scanners to check your system with.
Edited by rp88, 06 February 2015 - 01:52 PM.
Back on this site, for a while anyway, been so busy the last year.
My systems:2 laptops, intel i3 processors, windows 8.1 installed on the hard-drive and linux mint 17.3 MATE installed to USB