- Install Linux Mint, taking the "Use entire disk" option.
All your Windows problems and viruses will disappear.
OK, though this is good advice for most casual users, it's not always practical. I need a Windows 7 machine so that I can test websites in Internet Explorer 9, for instance. Other people have to run business software that's Windows only - although you might be able to run it under Wine.
So, if you really must have Windows...
- Make sure it's at least Windows 7. Windows XP is an overpatched relic and Vista was only ever slightly less smelly and infected than an open sewer.
- Delete all the bloatware the manufacturer put on there. Likely candidates include:
- Trial anti-virus software that wants you pay after 30 days
- Trial Microsoft Office software - there's no need to pay for commercial quality office applications
- Free games, that probably cease being free after a month, or x plays
- Proprietary cloud services for backup or additional storage
Contol Panel>Uninstall applications is your friend.
- Install Google Pack. This will give you a whole bunch of useful stuff in one go, including free and sensible replacements for the stuff you just removed. Just take your pick from the list.
Note that you don't need more than one anti-virus product, if in doubt pick Avast.
- If you installed Avast at step 3, register it right now.
- If you are a serious wordsmith or spreadsheet user, download and install Libre Office.
This will let you read and write Microsoft Office documents so you can exchange files with all those 20th century throwbacks who still imagine it's a good idea to mail around bloated Word documents or vast Excel spreadsheets. (Try and persuade them to share using Google Docs, it will save duplication, bandwidth and time)
Libre Office is the worthy descendent of OpenOffice.org that has already extended with some useful features and is not bound up in Oracle's pursestrings. It will have all the features you need, is well documented and as easy to use as anything.
Now you have a sensible PC.