I would like to thank all of you for your help,
i found the problem, it was hibernate @ 13.5 Gb
and pagefile.sys (backup ram) matching my actual ram @ 16 Gb
The other Gig or so was just random files, but wow,
IM HAPPY TO HAVE MY £30 BACK
Thanks
For those with this problem and find this thread 2-3 years down the line;
disable hibernate feature by cmd type;
...................................................... powercfg -h off
reduce pagefile.sys by;
1- Go to your computer
2- Right click, properties
3- advance system settings
4- Go to Tab 'ADVANCE'
5- Under performance hit 'Settings'
6- Go to Tab 'ADVANCE'
7- Under Virtual Memory 'Change'
8- You can disable it but i wouldn't - just reduce it to its minimum operating amount which is 800Mb and set Max @ 1000Mb.
I presume this isn't just a SSD thing, so if you need some space and you hae high amount of RAM and dont use hibernate, Check this out.