Mon–Fri 09:00–16:00 |4.8/5 on TrustedShops |19,000+ satisfied customers |German company
Mon–Fri 09:00–16:00 4.8/5 on TrustedShops 19,000+ satisfied customers German company Mon–Fri 09:00–16:00 4.8/5 on TrustedShops 19,000+ satisfied customers German company
SKU 1A-50

Windows 8.1 Professional

Immediate delivery by email

·

One-time purchase · No subscription · Usable permanently

Already 4.366-times sold
Instant activation
Free installation support
Legal & verified product key
Instant delivery by email
only 9,90 € 34,90 €

Tax included

You save 25,00 €
Best price in the shop Currently the best deal for this product
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Immediate delivery

Key by email.

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Contact

Mon–Fri, 9 AM–4 PM

Why are our prices so low?

Transparency is important to us. That’s why we offer you high-quality software at fair prices.

Direct Purchase

We buy product keys in large quantities directly from authorized distributors – and pass the price advantage on to you.

Digital only

No physical shipping, no inventory, no packaging. This saves costs that you don’t have to pay.

Low margin

We focus on volume rather than high margins. Many satisfied customers are our business model.

Legally compliant & verified

All product keys are approved for resale in accordance with EU law (ECJ ruling C-128/11).

In 3 steps to your software

Activated software in just 3 steps

1

Order

Select product and pay securely

2

Get key

Product key immediately by email

3

Activate

Download the software, enter the key, done!

Done! Your software is ready to use.

Complete your setup

Frequently bought together

AK
LS
MR

We are here for you

Real people, real support! Our team is happy to help you with installation, activation, or any questions. Mon–Fri: 9 AM–4 PM.

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Frequently Asked Questions

Everything you should know before buying

Case law on used software

As the highest judicial authority of the European Union, the Court of Justice of the European Union (CJEU) provided final clarity with its ruling and declared the trading of used computer programs fundamentally lawful.

The CJEU also ruled that trading in used software is permissible even when the software is transferred online.

On July 17, 2013, the Federal Court of Justice fully confirmed the CJEU’s landmark decision with regard to the underlying legal questions. 

The CJEU ruling also applies to volume licenses and their splitting. This was confirmed by the Higher Regional Court of Frankfurt am Main in proceedings between Adobe and usedSoft.

In their reasoning, the 13 judges of the Grand Chamber clearly established that the exhaustion principle applies to every first sale of software. The CJEU even ruled that a subsequent purchaser may download the software again from the manufacturer in the case of licenses transferred online: “Furthermore, the exhaustion of the distribution right extends to the program copy in the version improved and updated by the copyright holder,” the CJEU stated. The Court thus went significantly beyond the opinion of the CJEU Advocate General of April 24, 2012.

VOLUME LICENSES AND THEIR SPLITTING ALSO LEGAL

In a later ruling by the Higher Regional Court of Frankfurt am Main in proceedings between Adobe and usedSoft, the further implications of the CJEU ruling were impressively confirmed: The Frankfurt Higher Regional Court held that the CJEU ruling also applies to volume license agreements and their splitting. The Federal Court of Justice dismissed Adobe’s appeal in its entirety on December 11, 2014 (Case No. I ZR 8/13). This conclusively confirmed the Frankfurt Higher Regional Court’s ruling. 

According to Microsoft's license terms, the product key is intended for one-time activation. The period of use is unlimited as long as the product is used on the same device. If the computer is reformatted, reinstalled, or any hardware changes are made, there is no longer any guarantee that the key will continue to work on the PC. In addition, you are prohibited from activating the key on multiple devices; see Microsoft's Terms of Use.(https://www.microsoft.com/de-de/rechtliche-hinweise/nutzungsbedingungen.aspx)

 See also Microsoft Privacy Statement
(https://privacy.microsoft.com/de-de/privacystatement/).

You can find the license terms for your respective product at https://www.microsoft.com/de-de/useterms There you can select the product for which you want to purchase the product key and view the specific license terms. 

If a key does not work as expected, contact our support – we will promptly replace the key or refund your full purchase price. 30-day money-back guarantee.

Usually within 30 seconds after payment is received via email. For bank transfers, it may take 1-2 business days.

Yes, you will automatically receive a proper invoice with VAT shown by email.

No! This is a one-time payment. No subscription, no hidden fees. The license is valid permanently.

Yes, our support team helps you with installation and activation for free – via live chat, email, or phone.

Note: We distribute Microsoft®️ operating systems as a reseller. There is no direct contractual relationship between the customer and Microsoft Corporation. Microsoft®️ is a registered trademark of Microsoft Corporation.

Instant download

Windows 8.1 Professional – Proven operating system for stable business environments

Welcome to officekey24 – your expert for genuine Microsoft software. Windows 8.1 Professional is the ideal solution for businesses and home users, that prioritize maximum stability, high compatibility, and reliable performance. Particularly suitable for older devices or specialized software that is not compatible with newer Windows versions.

Perfect for classic systems & specialized applications

Windows 8.1 Pro offers professional features such as domain joining, advanced security options and stable system performance. If you are looking for a newer version, you can also find:

Your benefits at officekey24

  • Immediate delivery by email
  • Original product key
  • Direct Microsoft download
  • Ideal for older PCs & business software
  • Easy activation
  • German customer support

The most important features of Windows 8.1 Professional

High stability

A proven system for long-term use.

Professional networking features

Domain integration and management for businesses.

Optimized for older hardware

Resource-efficient and effective.

Broad software compatibility

Supports programs that no longer run on Windows 10 or 11.

System requirements

Processor 1 GHz or faster (32-bit or 64-bit)
Memory 1 GB (32-bit) or 2 GB (64-bit)
Storage space 16 GB (32-bit) or 20 GB (64-bit)
Graphics DirectX 9 compatible
Internet Required for download & activation

For further details, please visit the manufacturer Microsoft.

Included in delivery

  • Product key for Windows 8.1 Professional
  • Installation guide
  • Download link
  • Customer support from officekey24