From system files to your browser’s data, there are some files that are better left untouched. Below is a list of files that you should skip when you’re on your next cleaning spree.

Don’t delete system files

This is pretty obvious, if the file is inside any of the system folders such as System32, Windows etc, do not delete them. In the operating system drive (usually C), there will be pagefiles and hibernation files. Don’t delete them as they are there for some reason, and the system needs those files for proper functioning.

Selectively clean the browser cache

It’s true that if you clean the web-browser’s cache, cookies and other session information, the browser will run faster. However, if you decide to wipe the cache files, you will probably have to log in to all the accounts, as all the session information is likely gone. A better way is to selectively clean the browser cache – removing only the tmp files, history etc, but keeping the browsing session intact.

Not all programs are to be removed

Removing unused applications is another great idea to free up some space from your computer. But are you sure about the software you are about to remove? Some of the software listed in the “Programs and Features” are driver modules, and in one way or the other help some other program. If you’re not sure about the file, it is advised you leave it untouched. There is a handy freeware tool, Should I remove it, that will tell you whether or not it is okay to remove a particular application.

Don’t delete all the system restore points

Deleting some of the old system restore files make sense. Your computer already has a new system restore point which will be sufficient to get your computer running again if something goes wrong. But not all system restore points should be removed. It is advised to not delete the last two system restore files. You can also check System Restore Explorer, a freeware tool which helps to get detailed file information about your system’s restore points.

Don’t delete the prefetch folder

Much like a browser, the system collects information which it stores in a folder by the name “Prefetch.” This folder is located inside the Windows folder, and it stores several dozens of files. This existence of this folder has been the root cause of several debates. The truth is, the “Prefetch” folder contains information about boot files and the order of program execution. While its deletion won’t crash your computer, every time you will turn it on, it will first spend some time sorting those files again, resulting in slowing down the system’s boot speed.

Noteworthy mention

If you’re using any system cleaning app such as Ccleaner, always see the files it is about to delete. You can uncheck the cache and other settings files to save the trouble.