Using CCleaner: CCleaner is a freeware temp files and registry cleaner. We need to use this type of software because almost all the infection that occur through internet, come through the temp files, and unfortunately windows does not remove temp files automatically.
The best way to manage this is to install ccleaner (from ccleaner.com or from one of the several download links provided on their sites, such as filehippo.com etc) - set it so that it runs automatically with windows start (options > settings> Run Ccleaner when computer starts) -add recycle bin Cleaner > Advanced > check the box "Custom files and folders" Options > Include > Add Folder browse and select C:\RECYCLER or C:\RECYCLED in XP or C:\$Recycle Bin (in Vista)
(adding the recycle bin to the ccleaner helps a great deal, that will automatically remove the files from the recycle bin, it is necesary for your protection, because the latest security threats add virus files inside the recycle bin which are executed when the computer restarts. )
Run the Cleaner and the registry menus in CCleaner. One thing to be pointed here is that the automatic running of ccleaner, runs only one menu in it , that is the Cleaner. You will also need to run the second menu called Registry once in a while, particularly if you are trying to remove a virus from your computer.