Before upgrading to Windows 11, it is advisable to free the Windows 10 computer from legacy issues. To remove software that is no longer required, use the on-board tools provided by Windows.

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Before switching to Windows 11, it can’t hurt to declutter your PC.
1.
First, get an overview of the current utilization of your system drive. To do this, open the Settings app with the keyboard shortcut Win-I. Click on “System” in the window and then on “Storage” in the bar on the left.

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2.
On the right side of the window, Windows shows you the memory usage of the system disk (usually C:). This is where the sizes for categories such as Apps & Features, Pictures, OneDrive, Documents, Email, and Temporary Files appear. “Other” is a collective category – clicking on it provides details on the folders considered. A click on the text link “Show more categories” shows all categories.

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3.
Clicking on “Apps & Features” takes you to the list of all installed programs, which you can sort by size. Below you can see which applications eat up the most storage space. You can delete programs that have never been used or are no longer required: To do this, click on the respective program name and then on “Uninstall”.

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4.
In the “System Reserved” category, Windows provides information about the space requirements of the files used by the operating system. It also tells you how much space is occupied by the memory swap file, hibernation dump, and system recovery data. The disk space that Windows 10 may reserve for future updates is also listed here.

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5.
File remnants left behind by Windows or programs, as well as the contents of the recycle bin, often take up a lot of storage space. Click the back arrow in the top left and click Temporary Files on the right. Windows now determines which temporary files are present on the drive. Put a tick in front of all entries except for “Downloads”. With “Remove files” Windows deletes the marked data.

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6.
After cleaning up with the Windows on-board tools, you should use a specialist with the HDCleaner program. Install the free tool and then start it. Now click on the three-line menu in the top left and then on “Clean”. Check the “Browser Cleaner”, “System Cleaner”, “Plugin Cleaner” and “Registry Cleaner” boxes. Please select “Standard” as the cleaning mode. With a click on “Clean up the PC” you start the clean-up action, which may take some time.

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step 6
Data backup before Windows upgrade
Install AOMEI Backupper, launch the tool and connect an external hard drive (via USB or network). On the program interface, click on “New backup -› File backup -› +Folder”. Select the folder or folders you want to back up, such as My Documents. Click on “+Folder” again to add more data. In the line below you specify the target medium for the backup. The safest is a hard drive that you only use for backing up data. Daily, incremental backups are preset. However, you can change this using the “Schedule” button on the bottom left. Use “Start” to create the first, full backup.
Backup system:
In addition to folder-based backup, AOMEI Backup can store one or more whole partitions, i.e. the system in the case of Windows partition. Such a system backup offers the advantage that your system secured in this way can be restored with all settings. Problems that have arisen in the meantime, which cannot be solved otherwise or can only be solved with difficulty, are simply overwritten and deleted. Important: Because no distinction is made between “bad” and “good” data when restoring, be sure to save your personal data on a different partition. Without this separation, these are also overwritten.
See also:
Windows 11 – upgrade or better a new installation?