I'd like to give a strong recommendation for ( OFFICE 2016 PRODUCT KEY ) for Microsoft keys and software. Windows Embedded 8.1 Industry Pro Nmmpb-38 Dd4-R2823- 62 w8d-vxkjb Windows 8 PRO: Xhq8n-C3mcj-Rqxb6-Wchyg-c9wkb Windows 8.1 Professional Xky4k-2 Nrwr-8 f6p2- 448 RF-cryqh.Windows 8.1 Core / Home Fb4wr-32 Nvd-4 Rw79-Xqfwh-cyqg3 Nttx3-Rv7vb-T7x7f-Wqyyy Y92f Pro-9 Use this key during installation ' to activate. Windows 8.1 Enterprise N TT4HM-HN7YT-62K67-RGRQJ-JFFXW Windows 8.1 Enterprise MHF9N-XY6XB-WVXMC-BTDCT-MKKG7 Windows 8.1 Professional N HMCNV-VVBFX-7HMBH-CTY9B-B4FXY Windows 8.1 Professional GCRJD-8NW9H-F2CDX-CCM8D-9D6T9 The trial/preview version will expire very soon, if you still need it please use the following key: Which Windows 8.1 are you talking about ? You don't have to use key to upgrade from Windows 8 to Windows 8.1. Windows Embedded 8.1 Industry Enterprise FNFKF-PWTVT-9RC8H-32HB2-JB34X Windows Embedded 8.1 Industry Pro NMMPB-38DD4-R2823-62W8D-VXKJB Windows 8 PRO: XHQ8N-C3MCJ-RQXB6-WCHYG-C9WKB Windows 8.1 Professional XKY4K-2NRWR-8F6P2-448RF-CRYQH.Windows 8.1 Core/Home FB4WR-32NVD-4RW79-XQFWH-CYQG3 Use this key after install to add features Use this Key during installation to activate.