Firstly, Download a free programme called Ccleaner, what it does it deletes all your cookies, history on your computer, So make sure any websites you want you add to favourites.
In this Picture i have deleted over 200mb, once i got over 2.5gb deleted. thats alot of memory for my laptop.
Step 1: Empty the recycle bin
Make sure you empty your recycle bin as it may have big files in there you dont want.
Step 2: End any programme
end any programme you dont need as it takes up time from where you are using it. unless you are downloading anything from a torrent site like vuze if you are downloading something ;)
Step 3: Uninstall any programmes you dont need
if you dont use any programmes, uninstalling them will save memory and make the laptop/computer faster
Step 4: Upgrade your ramm
Upgrading your ramm will make you compuer/laptop alot faster. getting the right one for your operating system is the thing so. go to a website called www.crucial.com
to find out