Windows stores information on drives, but before Windows can store any information on a drive, you need to put “shelves” on the drives, known as partitions. Although often a partition fills an entire drive, some drives contain several partitions, each with its own letter. And if you install a new, larger drive, when you reinstall Windows, its partition is still the original size — just on a larger drive. You can extend that partition to fill the entire drive.


Click the Start button, right-click Computer, and choose Manage from the pop-up menu that appears.

The Computer Management window appears, a launching point for lots of technical tasks.


Choose Disk Management from the Computer Management window’s left pane.

The window’s right side displays your disk drives and their partitions. Your C partition is identified by the characters “(C:)”, along with the words “System,” “Boot File,” “Page File,” and other technical verbosity. (It also has a blue line across its top.) The space to the right on your C drive is listed as “Unallocated,” meaning it’s not being used. (It has a black line across its top.) So, your mission is to extend your C partition’s boundaries to grab that unused space.


Right-click your C: partition and choose Extend Volume from the pop-up menu that appears.

The Extend Volume Wizard appears, ready to walk you through the process of extending your C partition to fill the entire drive. Click Next to start the wizard. The wizened wizard is sharp enough to know you want to extend your drive into the vacant space, so it offers you that option with its first screen.


Click Next to confirm that you want to extend the partition to fill the entire drive.

Because you want to fill the entire drive, don’t change any of the settings on this screen before you click Next.


Click Finish to confirm that you’ve chosen the right drive to extend.

A few seconds later, your partition fills the entire drive.