What do you mean by cache? You mean RAM usage? If it's that, the software you're using is consuming too much RAM, try alternatives. For browser, try Firefox with uBlock. For torrent, try Deluge. Music, Clementine. Etc.
You can also remove the windows animation effects. Write on google about "win7 god mode", it'll give you access to all configs, tune it for "performance", there's many options.
Also, press Win+R and type "msconfig". There you can choose programs that start at boot. Disable as much as you can.
You can also use BleachBit to wipe some shit.
Increase your swap:
http://www.thewindowsclub.com/increase-page-file-size-virtual-memory-windows

This script also could help:
https://github.com/bmrf/tron