CCleaner here is free

CCleaner (short for "Crap Cleaner") knows exactly where to find the files that slow down your computer. Get a quick understanding of CCleaner's features, and learn how to properly maintain your system to keep your computer quick and nimble.

Step 1: Focus your efforts

For a deep cleaning of your PC, you'll want to get into the nooks and crannies of your system. Using the Cleaner window (the default window when you launch CCleaner), you'll notice several checked boxes that indicate which areas of your computer will be cleaned. Most of the boxes are checked by default, so pay close attention if you only want to scrub certain areas. Tabs at the top offer the ability to clean Windows areas and other applications. Switching between the two tabs allows you to make your choices for a customized cleaning.

When you're done with your settings, click the Analyze button on the lower left to see which items will be cleaned. You'll see every file CCleaner will delete and also exactly how much memory will be returned to your system after the cleaning.

Note: It pays to peruse this list before hitting the Run Cleaner button to make sure you're not deleting something important. When you're ready, hit Run Cleaner and watch CCleaner go to work.

Step 2: Out with the old

The next step in our spring-cleaning protocol is akin to sorting through and cleaning out those old boxes in the garage. Click the Issues button on the left side of the interface to bring up another set of checked boxes. This set of tasks does everything from eliminating unused file extensions to trashing obsolete software. Uncheck the boxes you don't want to scan and click the Scan for Issues button. At the end of the scan you'll be given the option to click the Fix Selected Issues button.

Note: It is highly recommend you save your current Registry configuration at the prompt in case of a malfunction later. An additional window will ask if you wish to delete specific items. If you know of a specific item in the list that is not a problem, simply tell CCleaner not to fix it. Remember, if you save your configuration beforehand a mistake here is easily reversible.

Step 3: Uninstall and Startup manager

Windows comes with its own Add or Remove Programs utility, but it's often slow to load and not the easiest Control Panel item to configure. CCleaner quickly lists all of your active programs, and lets you highlight and uninstall software you no longer want. This part of the program utilizes tools already included in Windows, but the convenience and speed for quick uninstallations is tough to beat.

To manage your start-up programs, click the Startup button under the Uninstall button in the upper left of the interface. You'll see a list of active start-up items that launch when you boot up your system. Be very careful here: some items are not immediately identifiable and you wouldn't want to shut down your firewall, antivirus program, or any other important program.

Once you've run through the entire cleaning process, don't be surprised if your computer runs a bit faster. Depending on the capacity of your hard drive, you'll also free up a shocking amount of space if you haven't run a program like CCleaner recently.

I have never seen anyone complain that Ccleaner broke something.

If you want to be doubly sure, create a full Restore Point first.

Analyze and Run the Cleaner option first (once is enough) Then click Registry and Scan for Issues. Leave them all selected and Fix Selected. (you are prompted to Backup. Agree. I never bother myself.)

Scan and Fix again. It may take a few attempts with lots of issues.

Mine always leaves one that cannot be fixed (unused file extension).

Runtime Error on your Pinnacle may be just one of those things. Get worried if it repeatedly does it, not just twice.

Making sure you have backups of important files is more important than anything else. Systems can be rebuilt. Your personal files/music/videos cannot.

The default settings in CCleaner are very safe

run cleaner and let it remove everything it finds.

I have run the registry cleaning tool in CCleaner for years and never bothered with backing up and never had a problem.