It's hidden somewhere. Quite a few methods:
1) Start, Control Panel, Performance and Maintenance, Administrative Tools, Computer Management, Disk Management, Storage, right-click the Volume, Tools, Options, Check Now button, Select Options, Start.
2) Start, All Programs, Accessories, Windows Explorer (right where it is really handy!), Expand My computer, right-click the drive, Properties, Tools, Check Now..., Select Options, Start.
3) Start, right-click My Computer, Manage, Storage, Disk Management, right-click the Volume, Properties, Tools, Check Now..., Select Options, Start.
4) Double-click My computer on the Desktop (or Start, My Computer), select drive, File, Properties, Tools, Check Now..., Select Options, Start.
5) My Computer, right-click the drive, Properties, Tools, Check Now..., Select Options, Start.