Newegg has the Microsoft Windows 8.1 64-bit OEM, model no. WN7-00615, for $74.99 (99.99 – 25 coupon) with Free Shipping for a limited time. To get discount, use the coupon code: EMCPEWD37 at checkout.

The Microsoft Store is offering eligible students, faculty, and staff Windows 8.1 Pro Upgrade for $69.99 for limited time. This student-only discount requires verification of student status prior to purchase.

If you are currently running Windows Vista or XP, you will need Windows 8 Pro Upgrade; which the Microsoft Store is also offering for students for $69.99 for limited time. Upon installation you can update to 8.1 for Free.

If you currently have a personal computer running Windows 7, then you can upgrade to Windows 8.1 Pro (Professional). With Windows 8.1 Pro, you can connect and share your files with built-in SkyDrive. It also adds enhanced features if you need to connect to company networks, access remote files, encrypt sensitive data, and other more advanced tasks. The Pro Pack makes your PC or tablet ready for business by adding professional-grade features like BitLocker for encrypting your data, Smart Screen, Remote Desktop, and Windows Media Center.