Should I reinstall Windows 10

Installation of Windows 10 as an upgrade or a new installation

Microsoft still offers the option of upgrading to Windows 10 for free. But the way there is different. In addition to an upgrade of the existing Windows or a complete new installation, Microsoft also offers the option of installing Windows 10 in addition to an existing Windows. We present all three options in more detail in these instructions.

  • Windows 10 can still be installed free of charge with a valid Windows 7 or Windows 8.x license key.
  • If you have already installed Windows 10 on your PC, you do not need to enter a product key for the new installation and you can skip this query. Windows 10 then activates itself again automatically, even with a new installation.
  • An upgrade installation takes over all files, settings and programs, provided they are compatible with Windows 10.
  • A parallel installation of Windows 10 in addition to Windows 7 or Windows 8.x enables a "smooth" changeover to the current operating system.


Free upgrade for owners of Windows 7 or Windows 8.x.

Support for Windows 7 will expire for end users in early 2020. Although the date is still a long way off, you should be aware that you are using an operating system from 2009, which only offers new technologies and protection options against modern attacks with great effort.

But since many users still stick to Windows 7 - in contrast to the less popular Windows 8.x - Microsoft still offers the option of upgrading to Windows 10 free of charge.

Free assistive technology update

So far, Windows 7 or Windows 8.x users who rely on assistive technology have been able to upgrade to Windows 10 free of charge. This option will expire on December 31, 2017, as can be read on the English pages about the free upgrade. Since Microsoft does not define in more detail in its FAQ which auxiliary technologies are meant, nor does it require proof, an upgrade to Windows 10 can be carried out in this way until the end of the year. (Note: Microsoft has not yet removed the option.)

How do I install Windows 10?

For easy installation of Windows 10, you need the Windows 10 Media Creation Tool, which either offers an upgrade installation of Windows 10, i.e. Windows 10 installed over an existing Windows, or installation disk (USB stick or ISO image for burning) for a new one - or parallel installation created. With the Boot Stick you can install Windows 10 without a CD and set up a PC again. A boot stick is also the most convenient way to install it on a tablet.

Selection of the bit version: If possible, only install the 64-bit version of Windows 10. This is the only way to use RAM over 4 GB and avoid driver problems, as manufacturers gradually stop supporting drivers for 32-bit systems. If you are still using a 32-bit system, there is no avoiding a new installation, as you cannot upgrade to a 64-bit version without a clean installation.

Upgrade installation without data loss

An upgrade installation is carried out over an existing Windows and optionally takes over all files, settings, apps and programs such as an installed Office. You can also use it to reinstall Windows 10 over an existing Windows 10, which corresponds to the "Reset this PC" function of Windows 10 and is also known as "refresh".

Important information before an upgrade installation

In the event of an upgrade installation, you should consider a few things in advance.

Create image

As with any major action on the PC, you should also create a system image before upgrading to Windows 10. Your previous Windows, including all programs and settings, is saved in a backup and can be restored using an emergency data carrier from the program manufacturer, even if the system is no longer bootable. In a comparison test of image programs, we published many - including free representatives - on WinTotal. With the image and the corresponding rescue disk, you can approach an upgrade to Windows 10 much more relaxed.

Create space on SSD or hard drive

No matter how you proceed: Free up space on the Windows partition. It can be 15 to 20 GB. Delete the Temp folder, any large program packages that you can reinstall later, and use the disk cleanup, which since Windows 7 offers many options for safely deleting files that are no longer required.

Check recovery partition

The recovery partition can also cause a problem later. If, for example, you have worked with the EaseUS Partition Master up to version 10.5 on your system, it may, under certain circumstances, have incorrectly changed the ID of the recovery partition. This in turn acknowledges the upgrade with an error such as 80070003. How to resolve the error via the command line is described in the forum entry from Eigthforums from How to fix the error message: “Could not find the recovery environment”, if the ID for the recovery partition type is incorrectly set to OEM.

But even if the system reserved partition is less than 350 MB in size, the upgrade to Windows 10 may fail. You will then receive the error message “Windows 10 cannot be run on this PC. Below are the reasons. Reason: The partition reserved for the system could not be updated. "

Disk management (diskmgmt.msc) cannot solve the problem. But it works with a partitioner such as "MiniTool Partition Wizard Free". Use such tools to shrink the first Windows partition at the beginning and then enlarge the recovery partition to a size of 350 MB using the space that has been freed up.

Check hardware for compatibility
Whether your own hardware still runs under Windows 10 does not only depend on its age. Windows 10 supports a large number of devices “out of the box”. But check beforehand whether the device is still running under Windows 10. Older printers and scanners in particular cause problems here.

BIOS update

In forums one can read again and again that a BIOS update solves installation problems with Windows 10 for users. Therefore, check with the manufacturer of the mainboard to see whether they offer new BIOS versions for your mainboard. The exact type can be displayed with many tools such as SIV, CPU-Z, Speccy or Sandra Lite.

Remove any hardware that is not required beforehand

Another source of interference is external hardware. In the event of errors such as 0xC1900101-0x2000c, you should therefore disconnect hardware that is not required before the upgrade and reconnect it step by step after the upgrade.

Uninstall virus scanner

Uninstall any virus scanner, including Microsoft Security Essentials, before upgrading over an existing Windows. We have many readers for whom the virus scanner caused massive problems during the upgrade. Temporary deactivation is not sufficient in case of doubt. The scanner can be reinstalled later - if released for Windows 10. A virus scanner with a firewall can also be responsible for any Internet problems during an upgrade, as Bitdefender itself writes.

Perhaps with this step it is also time to think about the virus solution so far. Günter Born commented on the topic of antivirus solutions under Windows 10 in his blog. The Windows Defender included in Windows 10 is better than its reputation.

Uninstall "System Tools"

Many system tools are deeply anchored in the system. This includes not only third-party firewalls, image and backup or partition programs, but above all many tweak and tuning tools. From our own and other people's experience, we strongly advise you to uninstall such programs in advance, as they may not be compatible with Windows 10 and can also hinder the upgrade process.

Deactivate autostart programs

You should also deactivate Windows autostart entries, e.g. for monitoring card readers. Auxiliary programs such as starters or autoruns can be used for this.

Decrypt system drives

If you have encrypted your system drive with tools like TrueCrypt, you should cancel this encryption beforehand. With the exception of BitLocker, encryption is likely to cause problems during an upgrade.

Start the upgrade installation using the update tool or the installation data medium

If you have decided to upgrade and, for example, want to install Windows 10 over an existing Windows 7, start the Media Creation Tool or the installation disk created previously from the current Windows. Windows 10 is then installed over the existing Windows, optionally taking over all files, settings and programs, provided they are compatible with Windows 10.

Upgrade installation

You can also use "Change the elements to be kept" to specify that only the personal files or nothing at all should be transferred.

Upgrade installation

Free up space after the upgrade

After the upgrade from Windows, the old Windows remains on the system as Windows.old. To free up this space, you can use the disk cleanup by starting “cleanmgr” via Start-> Run. Alternatively, the program can also be found in the context menu of the system volume under Clean up in the properties.

Then click on “Clean up system files”.

There you can then mark the entries "Temporary Windows installation files" and "Previous Windows installation (s)" and free up so many gigabytes of storage space.

New (clean) or parallel installation

From our point of view, the better way instead of an upgrade installation is a new installation of Windows 10. The clean installation in particular frees you from unnecessary ballast, possible errors and incorrect settings in Windows compared to an upgrade installation. You should therefore restart the PC with a fresh Windows if possible.

With the installation medium, you have the choice of installing Windows 10 as the new operating system alongside the existing Windows 7 or Windows 8.x or as the only operating system on an empty hard drive.

The parallel installation in particular has the charm that you can continue to use the familiar operating system for the time being and at the same time also have the opportunity to try out Windows 10.

License key required

For the installation as a new installation or parallel installation, only a valid license key is required, which is either on a license sticker (on notebooks on the floor or hidden behind the compartment for the battery), in the firmware of the mainboard (is then used by Windows 10 during installation read out later) or on the outer packaging of the installation DVD.

Make space!

As a further step, you have to create space on the hard disk for Windows 10 for a parallel installation. If you only have one partition, you must first shrink it under Windows. The data carrier management (system control, administration, computer management) offers the right option for this.

Select the partition to be reduced and choose "Reduce volume" in the context menu.

Shrink through disk management

In the following dialog you can specify at what time the partition should be shrunk.

Shrink through disk management

For Windows 10 it should be at least 20 GB. If you have the space, however, 60 GB is a good guideline. Windows 10 will later be installed in this free space.

You may not be able to reduce the size of the partition as intended, despite possible free space. This is because Disk Management cannot move all files for shrinking. If these files, like the Master File Table (MFT), are in an unfavorable position, you will not get any further here. In this case, use partitioners such as AOMEI Partition Assistant, EaseUS Partition Master or MiniTool Partition Wizard to do the shrinking, and they will do the job with ease.

MiniTool Partition Wizard, resize

Custom installation

Start the system from the Windows 10 installation disk.

You now also have the option of installing Windows 10 as an upgrade of an existing Windows (see above under upgrade installation) or as a new operating system, also in addition to an existing Windows 7 or Windows 8.x and can then use the boot menu for more later than a Windows installation, select which system should be started. Therefore, select "User-defined" for the second variant.

Custom installation

In the dialog that follows, select the previously created partition or a new drive as "unallocated space". Windows 10 then installs itself as an additional system on the empty partition / hard disk and, after the installation is complete, sets up a multiboot if more than one system can be found on the hard disk.

When asked for the product key, you can enter the key of your Windows 7 or Windows 8.x license. Windows 10 is also being sold. The price for a full system builder version should be around 80 euros.

Installation without a key

If you had previously installed Windows 10 on the system, you can also click "I do not have a product key" and thus skip the entry. After an internet connection has been established, the license is automatically reactivated.

Set the default operating system

You can then switch between the two systems after the installation when booting in a parallel installation. You can specify which operating system is started automatically if you do not make an entry in the Control Panel under Windows 10, System, Advanced System Settings, Startup and Recovery.

Start behavior

Windows 10 only ever installs the Home Edition
Windows 10 usually asks during installation which edition (Home, Pro ...) should be installed. On systems that were delivered with a pre-installed Windows 8.x, this query is sometimes not required and Windows 10 is installed directly in the Home Edition. The reason is that manufacturers have been able to store a license key since Windows 8.x directly in the BIOS / EFI, which Windows 10 then recognizes and installs the edition stored there.

If you own a Pro edition of Windows 7 or Windows 8.x, you can use this license key for an upgrade.

After the installation, switch to the Activation section in the settings under “Update and Security”. Here you can upgrade to a higher edition (in our case Windows Pro) by clicking on "Change Product Key" and entering a valid license key for Windows 7 or 8.x Pro.

Upgrade the edition

After installation

After installation, check that all devices are working. The right starting point for this is still the device manager, which you can access via the classic system control or via the "My PC" context menu.

Device manager

Search for drivers over the Internet

If there is a device with a yellow exclamation mark, you should use the context menu of the faulty device with "Update driver" to have Windows automatically search for drivers. Windows' online search is often successful here and installs the missing driver. If this does not lead to success, look for the latest drivers on the homepage of the manufacturer of the component (or the mainboard) and install them manually.

Privacy settings

You should also take some time for the topic of data protection. Windows 10 offers a wide range of options for what Windows may or may not be allowed to do. The data protection settings have been significantly expanded compared to our first detailed analysis in the article Data protection in Windows 10 and can be accessed centrally via the settings.


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