It doesn't back up the entire contents of your storage device, so it may not help you if you can't boot Windows at all. A system restore is like a bookmark or snapshot that the operating system can go back to.

Windows uses System Restore to preserve system files in case they're accidentally deleted or corrupted. Then it will load a window that looks exactly like the analysis results window you saw in Disk Cleanup. This will perform another analysis, which can take a few minutes, especially if it detects those Windows Update backup files that we mentioned earlier. The biggest hoarders of your disk space are probably system files, so click the Clean up system files button to access them. We recommend leaving the Thumbnails item in Disk Cleanup unchecked, unless the cache size is creating problems with your available free space. If you're looking for a specific picture or video, you may have to wait until the thumbnail has been created, unless you know its file name. Each thumbnail will also take time to recreate, so a large folder may take several minutes to rebuild its cache. But if you clear out this cache, Windows will have to regenerate those images the next time you view a folder with a lot of media or icons in it. Thumbnails include things like app icons and picture previews. The Disk Cleanup tool has one list item specifically for thumbnails. Tom McNamara/CNET Dealing with thumbnails Some boxes are even prechecked, such as the one next to Temporary Internet Files.

Once that's done, you'll be presented with a new window containing a list of things that are safe to delete. If you have a lot of stuff to clean up, it may take the tool several minutes to analyze your situation and get your cruft organized for deletion. If this is the case, instead of typing 'disk cleanup,' type 'free up disk space.' A phrase may work when the name of the program doesn't. Sometimes the shortcut doesn't show up in your search results. You can also find the tool by right-clicking a storage device in File Explorer, selecting Properties, and clicking the Disk Cleanup button to the right of the pie chart. Click and drag this shortcut to your desktop or taskbar for easier access next time. Find it by clicking the Start button, typing 'disk cleanup' (whenever I say to type something, I mean without the quotes), and clicking the Disk Cleanup shortcut in your search results. Every storage device in your computer has access to the Disk Cleanup tool.

Crap cleaner cnet