My Dell laptop has been driving me up the wall lately as it was running so slow. Tried all the usual defrag etc. Eventually came across the Guardian it guys blog who recommends downloading CCleaner. Downloaded the free version.
My computer is literally fizzing now.Ran the cleaner utility which cleaned all the crap, then disk wiper, make sure you only use it to wipe the free space or it will wipe your data as well.
When downloading make sure you just download the free version (unless you want to buy the pro) when you get the license page up just press cancel.
Link here:
https://www.piriform.com/ccleaner/download