I keep my netbook in trim by using the following FREE Utilities which I acquire mostly from http://www.cnet.com/ a website I have been using for several years, where you can find lots of great software covering everything you could need. Be careful when installing though, as Cnet has it's own downloader, and so you have to be careful that you don't fall for the Opt Ins that you don't really need, for example search engines that would replace your favourite ones, or apps that you don't really need. Read the install details very carefully, and choose I Accept / I decline as you see fit.
Ccleaner - http://www.filehippo.com/
TweetUwrite and the TweetUwrite Desktop Application are (c)2011 by David G Griffiths