MICROSOFT CORP files 424B2: prospectus (424B)

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement is not an offer to sell the securities and is not soliciting an offer to buy the securities in any jurisdiction where the offer or sale is not permitted.

Microsoft Corporation

We are offering $ aggregate principal amount of Floating Rate Notes due 20 (the “20 Floating

Rate Notes”), $ aggregate principal amount of % Notes due 20 (the “20 Notes”), $ aggregate principal amount of Floating Rate Notes due 20 (the “20 Floating Rate Notes” and, together with the 20 Floating Rate Notes, the “floating rate notes”), $ aggregate principal amount of % Notes due 20 (the “20 Notes”), $ aggregate principal amount of % Notes due 20 (the “20 Notes”), $ aggregate principal amount of % Notes due

20 (the “20 Notes”), $ aggregate principal amount of % Notes due 20 (the “20 Notes”), $ aggregate principal amount of % Notes due 20 (the “20 Notes”), $ aggregate principal amount of % Notes due 20 (the “20 Notes”) and $ aggregate principal amount of % Notes due 20 (the “20 Notes” and, together with the 20 Notes, the 20 Notes, the 20 Notes, the 20 Notes, the 20 Notes, the 20 Notes and the 20

Notes, the “fixed rate notes” and the fixed rate notes, collectively with the floating rate notes, the “notes”).

The 20 Floating Rate Notes will bear interest at a floating rate, reset quarterly, equal to Compounded SOFR (as defined herein)

plus basis points ( %) per annum. The 20 Floating Rate Notes will bear interest at a floating rate, reset quarterly, equal to Compounded SOFR plus basis points ( %) per annum. Interest on the floating rate notes will accrue from , 2026 and be payable quarterly in arrears on , , and of each year, beginning on , 2027. Interest on the fixed rate notes will accrue from , 2026 and be payable semi-annually in arrears on and of each year, beginning on , 2027.

The 20 Floating Rate Notes will mature on , 20 , the 20 Notes will mature on , 20 , the 20 Floating Rate Notes will mature on , 20 , the 20 Notes will mature on , 20 , the 20 Notes will mature on , 20 , the 20 Notes will mature on , 20 , the

20 Notes will mature on , 20 , the 20 Notes will mature on , the 20 Notes will mature on , 20 and the 20 Notes will mature on

, 20 .

The floating rate notes will not be redeemable prior to maturity. We will have the right at our option to redeem the fixed rate notes in whole or in part at any time or from time to time at the redemption prices described under the heading “Description of the Notes—Optional Redemption of the Fixed Rate Notes.”

The notes will be our senior unsecured obligations and will rank equally with our other unsecured and unsubordinated debt from time to time outstanding.

See “ Risk Factors ” on page S-6 for a discussion of certain risks that should be considered in connection with an investment in the notes.

The notes will not be listed on any securities exchange. Currently, there are no public trading markets for the notes.

We expect to deliver the notes to investors through the book-entry delivery system of The Depository Trust Company and its direct participants, including Clearstream Banking, société anonyme , and Euroclear Bank SA/NV on or about , 2026, which is the business day following the date of this prospectus supplement. See “Underwriting” in this prospectus supplement.

Joint Book-Running Managers

The following is a brief summary of the terms and conditions of this offering. It does not contain all of the information that you need to consider in making your investment decision. To understand all of the terms and conditions of the offering of the notes, you should carefully read this prospectus supplement, as well as the accompanying prospectus and the documents incorporated by reference herein.

Issuer Microsoft Corporation

Securities offered $ aggregate principal amount of 20 Floating Rate Notes;

$ aggregate principal amount of 20 Notes;

$ aggregate principal amount of 20 Floating Rate Notes;

$ aggregate principal amount of 20 Notes

$ aggregate principal amount of 20 Notes; and

$ aggregate principal amount of 20 Notes.

Maturity date , 20 for the 20 Floating Rate Notes;

Interest rate floating rate, reset quarterly, equal to Compounded SOFR plus basis points ( %) per annum for the 20 Floating Rate Notes;

% per annum for the 20 Notes;

floating rate, reset quarterly, equal to Compounded SOFR plus basis points ( %) per annum for the 20 Floating Rate Notes;

% per annum for the 20 Notes;

% per annum for the 20 Notes;

% per annum for the 20 Notes;

% per annum for the 20 Notes;

% per annum for the 20 Notes;

% per annum for the 20 Notes; and

% per annum for the 20 Notes.

Interest payment dates Interest on the floating rate notes will be paid quarterly in arrears on , , and of each year, beginning on , 2027. Interest on the fixed rate notes will be paid semi-annually in arrears on and of each year, beginning on , 2027, and on the maturity date of each such series of fixed rate notes.

Optional redemption of the fixed rate notes We will have the right at our option to redeem any series of fixed rate notes, in whole or in part, at any time or from time to time prior to the maturity date, in the case of the 20 notes, and the applicable Par Call Date (as defined herein), in the case of the 20 notes, the 20 notes, the 20 notes, the 20 notes, the 20 notes, the 20 notes and the 20 notes, at the applicable make-whole price set forth in this prospectus supplement plus accrued and unpaid interest to the date of redemption . We will also have the right at our option to redeem the 20 notes, the 20 notes, the 20 notes, the 20 notes, the 20 notes, 20 notes and the 20 notes, in whole or in part, at any time on or after the applicable Par Call Date at the redemption price of 100% of the principal amount of the notes of such series to be redeemed plus accrued and unpaid interest to the date of redemption . See “Description of the Notes—Optional Redemption of the Fixed Rate Notes” in this prospectus supplement.

The floating rate notes will not be redeemable at our option.

Ranking The notes will be our senior unsecured obligations and will rank equally with our other unsecured and unsubordinated debt from time to time outstanding.

Further issuances We may from time to time issue further notes of any series ranking equally and ratably with the notes of such series in all respects, including the same terms as to status, redemption or otherwise.