As USB sticks and other flash memory drives increase in storage capacity, so does their popularity as software repositories. Many applications have developed special versions for these devices, usually known as "portable". One of them is CCleaner Portable.

In a few words, CCleaner Portable is the pocket version of CCleaner, an excellent cleaning tool with which you can erase unused files, thus gaining back valuable free disk space and making Windows run faster and smoother. The great advantage about CCleaner Portable is that it allows you to do just the same without leaving any evidence of use on the computer. In fact, you don't even need to install it. Simply run it from your USB memory stick and you'll have immediate access to all of its features. CCleaner Portable does create some necessary keys in Windows Registry, but these are deleted when the program is closed, so there'll be no trace of it left on the system.

Regarding its functions, CCleaner Portable does a very satisfactory job. The program helps you to get rid of many different files such as Internet cookies, temporary files, log files or all those leftovers found after months of installing and uninstalling applications. The configuration menu in CCleaner Portable features interesting options like the possibility to keep certain cookies which may be useful for you or the ability to add custom file types to the delete filter. Apart from freeing up disk space, CCleaner Portable also lets you uninstall applications, find broken registry keys and list all the programs set to run when Windows launches.

On the down side, CCleaner Portable does not allow you to undo changes, so you must be very sure about what you want to erase before clicking on "Yes". Also, the program can take a few minutes before finishing the analysis that must be done prior to deletion. However, this is probably due to the fact that CCleaner Portable runs from a USB device and that we checked all the available options when cleaning our system – the test found 558 MB of removable material, which obviously took a while to be deleted.

All in all, CCleaner Portable is every bit as good as its "big brother" and comes in really handy when you want to use it on any PC without installing anything or leaving any traces behind you.