Unbelievably Slow PC

[Chris-UK]

I'd also go down the route of clean install. This would take 30 minutes max (+ whatever time it takes to backup files) and would rule out any software issues. Double check you have at least your network drivers though first. Nothing worse than doing a reinstall only to find you don't have a driver disc and have no internet connection.

Also, this might sound obvious, but make sure you keep your expectations in check. I notice on your rig you have a Samsung EVO SSD. Its very easy to get used to the speed of an SSD and take it for granted
If investing money is an option then you could pick up a 120GB SSD for about £50 and reuse the existing drive for storage. Would make a huge difference to performance.

[mazty]

http://www.dban.org/ <- run that, then a fresh install. Works every time.

[Galant]

Coming at this from another angle - when the machine is switched on does it sound like a jet-engine? Might be something simple like dust clogging the heat-sink. The amount of times this has been an issue for machines I've seen...well as usual - if I had a quid...

If you're confident in your hardware, open it up, and take a look at the heat-sink/fan. If it's dusty then consider stripping out the heat-sink and giving it a good clean out.

[naromOG]

Try downloading AVG TuneUp 2014 - its great, and it comes with a 30 day trial